Public Companies Research Articles

Is the mortgage model appropriate for financing hospitals? A case study

ABSTRACT Objective To evaluate the cost–benefit of a PPP (Public Private Partnership) model -mortgage model- compared to traditional budgeting method funding models based on traditional public budgets (TM). Methods The economic-financial evaluation of the construction has been carried out under the PPP model of a hospital in the Northern Galicia–Portugal–Euroregion by performing a simulation analysis. This comparison involves an analysis of the life project, expressed in terms of net present value (NPV) of the costs and benefits of the project proposed compared to the costs and benefits of the provision of the service by the traditional budgeting method (TM). A simulation analysis has been also performed. Results The PPP (Public Private Partnership) project does not offer more value for money than the traditional budgeting funding model (Public Budget –TM-) – defined as an alternative to the public sector for the provision of the same services. Conclusion The best option would be the creation of a public company (Public Society of Investment –SPI-) to finance the construction and commissioning of the hospital.

Naapbooks Limited: an innovative IT solution for SMEs

Learning outcomes This case study will frame the significance of the business model for a company. The reader will understand business model innovation and how it helps enhance entrepreneurial rewards. The students will be able to identify the entrepreneurial traits which lead to business model innovation. The readers will know about the components of a business model and will be able to apply the understanding in creating a business model canvas. Case overview/synopsis The real-life case is of a tech start-up founded in Ahmedabad by three friends. Their diverse educational background helped them in creating a successful venture that later transformed into a public company. They were always trying to make their business model competitive and innovative. Being a start-up, there were critical business decisions taken and strategies formed by the founding team. They were facing a dilemma after making the company public, as their responsibility towards the stakeholders increased. They need to keep in mind the needs of all the stakeholders and the enterprise itself. They were at a crossroads in deciding about their business model. Complexity academic level This case study is suitable for honours or postgraduate level or entrepreneurship training. Supplementary materials Teaching notes are available for educators only. Subject code CSS 11: Strategy.

Akulaku E-Commerce Company's Public Relations Marketing Strategy in Building Brand Awareness

Akulaku E-Commerce Company's Public Relations Marketing Strategy in Building Brand Awareness

Criminal liability of public transportation companies for traffic accidents caused by vehicle unfitness

This study investigates corporate criminal liability in public transportation accidents caused by vehicle unfitness, a pressing issue in Indonesia’s road safety framework. While Law Number 22 of 2009 on Road Traffic and Transportation (UU LLAJ) aims to promote safety, it predominantly emphasizes driver accountability, leaving corporate negligence largely unaddressed. The research aims to analyze the gaps in the legal framework and propose reforms to ensure corporations are held accountable for their roles in maintaining vehicle roadworthiness. Using a normative legal research design, this study integrates statutory analysis, case law review, and conceptual exploration to examine corporate liability frameworks. Legal theories such as vicarious liability, identification theory, and delegation theory are utilized to conceptualize corporate accountability. Case studies and international legal comparisons provide insights into enforcement challenges and best practices. The findings reveal significant deficiencies in UU LLAJ, including ambiguous provisions and weak enforcement mechanisms, leading to systemic non-compliance. Proposed reforms include stricter penalties for corporate negligence, enhanced vehicle inspection protocols, and expanded legal provisions targeting corporate accountability. This study contributes to the discourse on corporate liability by bridging theoretical principles with practical enforcement in Indonesia’s transportation sector. Its implications extend to policy reforms, road safety improvements, and fostering a culture of accountability within the industry.

P-605. Bivalent RSV Prefusion F-Based Subunit Vaccine Generates High and Durable Neutralizing Titers Across an Entire RSV Season among Older Adults

Abstract Background Pfizer’s bivalent respiratory syncytial virus prefusion F subunit vaccine (RSVpreF [ABRYSVO™]) was approved in the United States for prevention of lower respiratory tract infections (LRTI) caused by RSV in individuals ≥60 years. The objective of this analysis is assessing the durability of RSVpreF vaccination on immunologic response over time.Figure 1.RSV A GMTs and GMFRs by Time Interval After Vaccination with RSVpreF, by Country- Evaluable Immunogenicity PopulationGMT= geometric mean titer; GMFR= geometric mean fold rise Methods The bivalent RSVpreF Efficacy Study was a phase 3, global, randomized, double-blind, placebo-controlled study evaluating VE for RSV-LRTI in adults ≥60 years over two RSV seasons (NCT05035212). A total of 36862 participants received RSVpreF or placebo (1:1) starting in August 2021. VE for LRTI-RSV with 3 or more symptoms was 88.9% (53.6, 98.7) in Season 1 and 77.8% (51.4, 91.1) in Season 2. The immunogenicity subset from selected sites included 1150 participants enrolled in the United States and Japan. Blood samples were collected at baseline prior to vaccination, 1 month post vaccination, and planned prior to the start of the second RSV season. Based on follow-up timelines, serology was draw in US participants (N=307) 8-12 months after vaccination and in Japanese participants (N=230) 18-20 months post vaccination.Figure 2.RSV B GMTs and GMFRs by Time Interval After Vaccination with RSVpreF, by Country- Evaluable Immunogenicity PopulationGMT= geometric mean titer; GMFR= geometric mean fold rise Results Overall, RSV GMTs increased substantially after vaccination with RSVpreF (GMFR was 11.6 and 12.7 at 1-month postvaccination for RSV A and B respectively) and remained high at pre-Season 2 (GMFR was 4.7 and 4.8); while remained the same as baseline for placebo group (GMFR ranged from 1.1 to 1.3 for both RSV A and RSV B at both timepoints). When further analyzing data at pre-Season 2 timepoint for RSVpreF, both RSV A (figure 1) and RSV B (figure 2), GMTs remained persistently elevated well above pre-vaccination levels 8-12 months post vaccination among US participants (RSV A GMFR range: 3.2-4.5; RSV B GMFR range: 3.5-4.8) and 18-20 months among Japanese participants (RSV A GMFR range: 5.1-6.2; RSV B GMFR range: 5.3-6.0). Conclusion Vaccination with RSVpreF elicited a strong immune response in adults ≥60 years to both RSV A and B and remained durable throughout the first RSV season up to 18-20 months after vaccination, during a time when high VE was demonstrated. This analysis provides further data to support the importance of neutralizing titers in the VE of RSVpreF. Disclosures Tarek Mikati, MD,MPH, Pfizer, Inc.: salary|Pfizer, Inc.: Stocks/Bonds (Public Company) Qin Jiang, PhD, Pfizer: Salary|Pfizer: Stocks/Bonds (Public Company) Daniel P. Eiras, MD, MPH, Pfizer. Inc: Employee|Pfizer. Inc: Stocks/Bonds (Private Company) John Woodside, PhD, Pfizer: Stocks/Bonds (Public Company)|Pfizer, Inc.: salary|Pfizer, Inc.: Stocks/Bonds (Public Company) Michael Patton, B.Sc., Pfizer: Employee|Pfizer: Stocks/Bonds (Public Company) Kumar Ilangovan, MD, MSPH, MMCi, Pfizer, Inc.: salary|Pfizer, Inc.: Stocks/Bonds (Public Company) Elena Kalinina, PhD, Pfizer, Inc.: Salary|Pfizer, Inc.: Stocks/Bonds (Public Company) David Cooper, PhD, Pfizer, Inc.: Employee|Pfizer, Inc.: Stocks/Bonds (Public Company) Kena A. Swanson, Ph.D., Pfizer: Employee of Pfizer|Pfizer: Stocks/Bonds (Public Company) Annaliesa S. Anderson, PhD, Pfizer, Inc.: Employee|Pfizer, Inc.: Stocks/Bonds (Public Company) Alejandra C. Gurtman, M.D., Pfizer, Inc.: Employee|Pfizer, Inc.: Stocks/Bonds (Public Company) Iona Munjal, MD, Pfizer: Salaried employee|Pfizer: Stocks/Bonds (Public Company)

628. Geographic distribution of hospitalized severe malaria cases in the United States, 2012–2018

Abstract Background Between 200–300 severe malaria cases are diagnosed annually in the U.S. Intravenous artesunate (IVAS), the FDA-approved 1st-line therapy for severe malaria since 2020, is commercially available but at high cost. Uncertainty regarding where people with severe malaria will seek medical care poses supply chain challenges. We identified hospitals where people with severe malaria were treated and mapped proximity to Level 1 trauma centers as a proxy for hospitals that provide complex clinical care, which could assist with planning for IVAS distribution. Location identification and manual adjudication process for hospitals that hospitalized people with severe malaria as reported to CDC from 2012–2018. Of the original 1,912 cases of severe malaria reported to the CDC from 2012-2018, we excluded 379 cases that were not admitted or were admitted but missing a hospital name. Of the remaining 1,533 severe malaria cases that were eligible for adjudication, 1,237 were an exact match with an existing hospital location. Of the 296 cases that were not an exact match, we manually adjudicated 229 cases by clarifying a hospital name that was abbreviated, incomplete, or had a change in name; only 49 cases could not be identified given multiple possible sites with the same name, and 18 cases with no name that matched a hospital site. Six additional cases were excluded because of occurring at a site with no Level 1 trauma center within driving distance (i.e., Alaska and US Virgin Islands). Methods Using 2012–2018 data reported to the Centers for Disease Control and Prevention (CDC), we analyzed free text of U.S. hospital names where people were treated as inpatients for severe malaria. We identified these hospitals using Google Maps Geocoding Application Programming Interface (API) followed by manual adjudication. We excluded cases when data were incomplete or ambiguous or if a Level 1 trauma center was inaccessible (e.g., Alaska or U.S. Virgin Islands). We then mapped hospitals to U.S. counties and estimated travel times between hospitals and the nearest Level 1 trauma center as per 2014–2016, using Google Maps Distance Matrix API. Average numbers of severe malaria cases at identified hospitals per US county annually as reported to the CDC during 2012–2018. Panel A shows the geographic distribution and average number of severe malaria cases at identified hospitals per year by county reported to CDC during 2012–2018; darker color shows counties with more severe malaria cases reported. Panel B shows that the distribution is highly skewed to 2 counties that reported more than 10 inpatient cases annually; 2,824 counties (pale peach) reported no cases of severe malaria admitted to an identified hospital during 2012–2018. Results After excluding 379 cases with no recorded hospital name from 1,912 severe malaria cases, we successfully adjudicated hospitals for 1,460/1,533 cases (Fig 1). Two counties reported >10 inpatient cases per year (Bronx County, NY and New York County, NY), and 2,824 counties never reported a hospitalized severe malaria case (Fig 2). Almost 35% of inpatient cases occurred at Level 1 trauma centers (508/1,460 [34.8%]) (Fig 3). Of the 952/1,460 (65.2%) inpatient cases not at Level 1 trauma centers, 891/952 (93.5%) were at hospitals located < 2h estimated driving time of a Level 1 trauma center. Only 61/1,460 (4.2%) cases were at locations >2h from a Level 1 trauma center. Limitations include that the analysis did not consider the original site of clinical presentation with malaria or locations of people with severe malaria not hospitalized. Histogram of modeled travel times between each severe malaria case at an identified hospital and the nearest Level 1 trauma center. Of severe malaria cases reported to CDC in 2012–2018 and hospitalized at an identified hospital, 34.8% were treated at Level 1 trauma centers (red bar); for severe malaria cases that were not at Level 1 trauma centers, we found that modeled transit times between treatment site and Level 1 trauma center were less than 2 hours except in 4.2% of severe malaria cases at an identified hospital (right of black dashed vertical line). Conclusion More than 95% of people admitted for severe malaria at identified hospitals reported to the CDC in 2012–2018 were at or within 2h estimated driving time of a Level 1 trauma center, which may suggest priorities for implementing IVAS distribution. Disclosures Alison Ridpath, MD, MPH, Abbvie Inc.: Stocks/Bonds (Public Company)|Amarin Corperation PLC: Stocks/Bonds (Public Company)|Amgen Inc: Stocks/Bonds (Public Company)|BioNTech: Stocks/Bonds (Public Company)|Immunic Inc: Stocks/Bonds (Public Company)|infinity Pharmaceutical Companies: Stocks/Bonds (Public Company)|IQVIA Holdings Inc: Stocks/Bonds (Public Company)|Johnson and Johnson: Stocks/Bonds (Public Company)|Merck and Co inc: Stocks/Bonds (Public Company)|Pfizer Inc.: Stocks/Bonds (Public Company)|Protagonist Therapeutics: Stocks/Bonds (Public Company)

594. A Phase I, Multicenter, Randomized, Double-blind, Placebo-controlled Single Dose, Dose-ranging Study to Evaluate the Safety, Tolerability, and Immunogenicity of Orally Administered Bivalent GI.1/GII.4 Norovirus Vaccine in Healthy Lactating Females ≥ 18 years Old and Their Breast-feeding Infants

Abstract Background There are no licensed vaccines to prevent norovirus (NoV) illness, a leading cause of gastroenteritis that can result in severe/fatal outcomes in infants. An effective NoV vaccine may target two leading genotypes causing human NoV infection worldwide, GI.1 and GII.4. Clinical trials have shown our bivalent nonreplicating adenoviral-vector based NoV vaccine candidate to be safe, well-tolerated, and highly immunogenic. Labayo et al. demonstrated NoV positive mothers with high breastmilk NoV antibodies had breastfed infants with less severe NoV disease; here, we will report the safety and immunogenicity of our bivalent GI.1/GII.4 NoV vaccine candidate in healthy, lactating females and their breast-feeding infants. Graph 1. Breastmilk anti-VPI GI.1 IgA was quantified by MSD at Days 1, 8, and 29. Mean Fold Rises were evaluated from Day 1 to Day 1, from Day 1 to Day 8, and from Day 1 to Day 29. There is a progression of GI.1 IgA production during the first 28 days post-vaccination in the medium and high dose groups. Methods 76 lactating females ≥ 18 years old and their breast-feeding infants > 30 days to 11 months of age were randomized to receive a single oral dose of bivalent VXA-G1.1-NN and VXA-G2.4-NS at medium dose 1×1011 infectious units (IU) (n=30), high dose 2×1011 IU (n=30) or placebo (n=16). Primary safety endpoints include solicited adverse events (AEs) for one week post dose and unsolicited AEs for 28 days post dose. Serum immunogenicity and breast milk antibodies were quantified by anti-VPI GI.1 and anti-VPI GII.4 IgA by Meso Scale Discovery (MSD) at Days 1, 8, and 29. Serum IgG was evaluated at the same timepoints. Graph 2. Breastmilk anti-VPI GII.4 IgA was quantified by MSD at Days 1, 8, and 29. Mean Fold Rises were evaluated from Day 1 to Day 1, from Day 1 to Day 8, and from Day 1 to Day 29. There is a progression of GII.4 IgA production during the first 28 days post-vaccination in the medium and high dose groups. Results All doses of vaccine were well-tolerated. Solicited symptoms were similar to prior studies and without grade 3 or 4 events. There were no serious AEs reported to date. Breast milk GI.1 IgA rose 4x above baseline in the high dose group on Day 29. Breast milk GII.4 IgA rose 6x above baseline in the high dose group on Day 29. Serum GI.1 IgA rose 3.4x for the medium dose and 2.7x for the high dose and GII.4 IgA rose 2x for the medium dose and 3.5x for the high dose on Day 29. Serum GI.1 IgG rose 3.4x for the medium dose and 5.1x for the high dose and GII.4 IgG rose 3.3x for the high dose on Day 29. Graph 3. Serum immunogenicity antibodies were quantified by anti-VPI GI.1 IgA and IgG and anti-VPI GII.4 IgA and IgG by MSD at Days 1, 8, and 29. Mean Fold Rises were evaluated from Day 1 to Day 1, from Day 1 to Day 8, and from Day 1 to Day 29. Conclusion Vaxart NoV bivalent vaccine candidate was safe and well-tolerated and elicited robust immune responses including the production of breastmilk NoV IgA in healthy, lactating female subjects. These results are an important step in the development of a NoV vaccine that is safe and immunogenic in lactating females with the potential to decrease disease severity in their breastfeeding infants. VXA-NVV-108 Topline Immunogenicity AnalysisTable 1.*Statistically significant Mean Fold Rise. Serum and Breastmilk anti-VPI GI.1 IgA and anti-VPI GII.4 IgA are primary endpoints for the study. Serum anti-VPI GI.1 IgG and anti-VPI GII.4 IgG are a part of the secondary endpoints. Disclosures Lam Nguyen, MD, CVS Health: Stocks/Bonds (Public Company)|Vaxart: Author is either employed and/or has received stock options from Vaxart as part of this work.|Vaxart: Stocks/Bonds (Public Company) Susan Greco, MD, MPH, Vaxart, Inc: Stocks/Bonds (Public Company) Becca A. Flitter, PhD, MPH, Vaxart Inc: Stocks/Bonds (Public Company) Molly Braun, PhD, Vaxart, Inc: TREATMENT OF LONG COVID WITH ORALLY AND MUCOSALLY ADMINISTERED ADENOVIRAL VECTORS|Vaxart, Inc: Stocks/Bonds (Public Company) Nicholas D’Amato, MSc., Vaxart Inc.: Stocks/Bonds (Public Company) Sean N. Tucker, PhD, Vaxart, Inc.: Grant/Research Support|Vaxart, Inc.: patent|Vaxart, Inc.: Ownership Interest|Vaxart, Inc.: Stocks/Bonds (Public Company) James F. Cummings, MD, VAXART: Stocks/Bonds (Public Company) Colin A. Lester, n/a, Vaxart, Inc.: Stocks/Bonds (Public Company) Darreann Carmela Hailey, MS, Bionano Genomics: Stocks/Bonds (Public Company)|Vaxart, Inc.: Stocks/Bonds (Public Company)

P-125. A Single-Center Descriptive Analysis of Cryptosporidiosis in Immunocompromised Patients

Abstract Background Cryptosporidiosis is usually a self-limiting infection caused by a protozoan, Cryptosporidium spp. In immunocompromised, especially with T cell dysfunction, it can cause severe, potentially life-threatening infection. There is limited literature on cryptosporidiosis in patients with malignancies. We aim to look for differences in patient characteristics amongst acute (< 2 weeks) and chronic (≥ 2 weeks) cryptosporidiosis in patients with cancer.Table 1:Baseline Characteristics of Study Population Methods A single-center, retrospective chart review on patients diagnosed with Cryptosporidiosis with the help of Gastrointestinal Multiplex (Biofire) was conducted at UT MD Anderson Cancer Center between November 2016 and November 2023. Data was collected from EPIC electronic medical records and analyzed using Fisher’s exact test.Table 2:Risk factors for Illness Results We identified 55 cases of cryptosporidiosis over 7 years. The date of first diagnosis was included in cases with multiple episodes. Among the 55 patients, 13 were excluded due to later confirmation of false positive results. Of 42 patients, the median age was 61 [IQR 24], 20 (48%) had non-hematologic malignancy and 21 (50%) had hematological malignancy [8 (19%) AML, 4 (9%) ALL, 3 (7%) MDS, 3 (7%) Lymphoma, 3 (7%) Myeloma]. 48% had hematopoietic stem cell transplantation, among which 35% were acute and 63% chronic. Within the last 90 days, 61% and 9% of acute cases, and 74% and 47% of chronic cases had received chemotherapy (p value= 0.514) and immunosuppressants (p value= 0.006), respectively. The median duration of symptoms prior to diagnosis was 3 days. Severe neutropenia was observed in 22% of acute cases and 42% of chronic cases, while severe lymphopenia was present in 57% of acute and 58% of chronic cases. Approximately 17% exhibited co-infection with other enteric pathogens, with most infections occurring in March, followed by October.Table 3:Clinical Presentation with laboratory and imaging, and Duration of therapy Conclusion In patients with cancer and cryptosporidiosis, co-infection with a second enteropathogen was common, and no seasonality was observed. The use of immunosuppressants was associated with diarrhea lasting more than 2 weeks. Cryptosporidiosis cases based on month Disclosures Pablo C. Okhuysen, MD, Astra Zeneca: Stocks/Bonds (Public Company)|Beam therapeutics: Stocks/Bonds (Public Company)|Biontech: Stocks/Bonds (Public Company)|Deinove Pharmaceuticals: Grant/Research Support|Ferring Pharmaceuticals: Honoraria|Glaxo Smith Kline: Stocks/Bonds (Public Company)|Haleon: Stocks/Bonds (Public Company)|Johnson and Johnson: Stocks/Bonds (Public Company)|Melinta pharmaceuticals: Grant/Research Support|Moderna: Stocks/Bonds (Public Company)|Napo Pharmaceuticals: Advisor/Consultant|Napo Pharmaceuticals: Grant/Research Support|Napo Pharmaceuticals: Honoraria|Novavax: Stocks/Bonds (Public Company)|Pfizer: Stocks/Bonds (Public Company)|Summit Pharmaceutical: Grant/Research Support

P-2095. Ultrasensitive Clostridioides difficile Toxin A/B Assay (in Development) for Higher Diagnostic Accuracy

Abstract Background Diagnostic tests for Clostridioides difficile infection (CDI) have either poor sensitivity or specificity, which has led to guideline recommendations for complex multistep testing algorithms. Ultrasensitive C. difficile toxin A/B measurements correlate with disease and may offer a standalone solution for CDI diagnosis. Fluxus develops ultrasensitive, target-agnostic, and low-complexity single-molecule diagnostic instruments based on optofluidic technology that combines integrated optics and microfluidics on a single chip-based system. Here, we report on the preliminary analytical performance of C. difficile toxin A and B assays (in development) powered by the Fluxus technology. Methods C. difficile toxin A (TcdA) and B (TcdB) were spiked into buffer and stool (pooled) and tested across a wide range of TcdA/TcdB concentrations to give dose-response curves and estimate limits of detection (LoD; assay background +2.5 STD of background) and quantification (LoQ; assay background +10 STD of background). TcdA and TcdB concentrations were calculated from a four-parameter logistic nonlinear regression-based calibration curve. Crossreactivity between the toxins was assessed. Further evaluation of expanded analytical and clinical performance is ongoing. Results LoDs in buffer for the prototype TcdA and TcdB assays were 0.47 and 0.98 pg/mL, respectively, and LoQs were 0.91 and 3.34 pg/mL, respectively, with a high dynamic range. LoDs in spiked stool for the TcdA and TcdB assays were 2.02 and 1.15 pg/mL, respectively, and LoQs were 4.25 and 4.35 pg/mL, respectively. There was no crossreactivity between the assay targets across a 4-log dynamic range. Conclusion Fluxus’ ultrasensitive C. difficile toxin A/B assays in development can detect TcdA and TcdB at pg/mL concentrations. Preliminary evaluation of spiked stool samples indicates a comparable dilution linearity to calibrator dose response in buffer. An ultrasensitive C. difficile toxin A/B assay has the potential to provide both high clinical sensitivity and specificity and may replace current testing methods. Disclosures Gipshu Dave, MS, Fluxus, Inc.: Stocks/Bonds (Public Company) Tiffany Truong, MS, Fluxus, Inc.: Stocks/Bonds (Public Company) Mariya Soban, MS, Fluxus, Inc.: Stocks/Bonds (Public Company) Justin Nguyen, BS, Fluxus, Inc.: Stocks/Bonds (Public Company) Frank Zaugg, PhD, Fluxus, Inc.: Stocks/Bonds (Public Company) Valerie Brachet, PhD, Fluxus, Inc.: Stocks/Bonds (Public Company) Peter Wagner, PhD, Fluxus, Inc.: Stocks/Bonds (Public Company) Johanna Sandlund, MD, PhD, Fluxus, Inc.: Stocks/Bonds (Public Company)

220. A Phase 2 Double-Blind, Placebo-Controlled Study Showing Oral Tableted Norovirus Vaccine VXA-G1.1-NN is Immunogenic, Efficacious, and Reduces Viral Shedding Following Norovirus Challenge

Abstract Background Norovirus (NV) is a leading cause of acute gastroenteritis worldwide. Currently no specific therapy exists for norovirus gastroenteritis (NVG). VXA-G1.1-NN is a nonreplicating adenovirus-vectored thermostable oral NV vaccine shown in clinical trials to be safe, well-tolerated and generates robust serum and mucosal immune responses. This study investigated safety, immunogenicity, and protective efficacy of VXA-G1.1-NN following NV GI.1 challenge.Figure 1.Clinical outcomes (norovirus infection and norovirus gastroenteritis) after norovirus challenge 28 days post vaccination with VXA-G1.1-NN or placebo Methods 165 healthy adults ages 18-49 were randomized 1:1 to a single oral vaccination of VXA-GI.1-NN or placebo. At 28 days post-vaccination, 141 eligible subjects were challenged with 1x106 genomic copies NV GI.1 inoculum. Solicited symptoms of reactogenicity were recorded for 1 week after vaccination and unsolicited adverse events (AEs) through 28 days post challenge. NVG was assessed by incidence of acute gastroenteritis (AGE) with evidence of NV+ infection. NV shedding was evaluated by qPCR in stool and emesis. VP1-specific GI.1 IgA antibody secreting cells (ASC), serum IgA and IgG, and Norovirus Blocking Antibody Assay (NBAA) were assessed. Totality of evidence analysis was used to assess overall vaccine protective effect.Figure 2.Viral shedding in stool by qPCR through 7 days post challenge with GI.1 NN virus inoculum following vaccination with VXA-G1.1-NN or placebo Results VXA-G1.1-NN was safe and well tolerated.VXA-G1.1-NN induced strong serum and cellular immunogenicity with substantial increases in VP1 GI.1- specific ASC and serum antibodies. Serum functional antibody responses, determined by NBAA, were significantly higher in subjects in the vaccine group compared to placebo. VP1 specific IgA was significantly increased in nasal secretions and saliva in the vaccine group. Protective efficacy for prevention of NVG was 21% (p= 0.149) and for NV infection was 29% (p= 0.003). An 85% decrease in geometric mean viral shedding in stool in the VXA-G1.1-NN group was also observed. Totality of evidence analysis for all 6 outcomes simultaneously provided a z-score of 5.56 (p< 0.001), indicating protective benefit of VXA-G1.1-NN.Figure 3.Cellular and serum immune responses following vaccination with VXA-G1.1-NN or placebo Conclusion VXA-G1.1-NN was safe, immunogenic, and reduced both viral shedding and NV infection following NV challenge. VXA-G1.1-NN tableted vaccine may help limit outbreaks by reducing viral shedding. Totality of evidence analysis for treatment effect provided a strong statistical signal supporting a protective effect of VXA-G1.1-NN. Disclosures Susan Greco, MD, MPH, Vaxart, Inc: Stocks/Bonds (Public Company) Becca A. Flitter, PhD, MPH, Vaxart Inc: Stocks/Bonds (Public Company) Lam Nguyen, MD, CVS Health: Stocks/Bonds (Public Company)|Vaxart: Author is either employed and/or has received stock options from Vaxart as part of this work.|Vaxart: Stocks/Bonds (Public Company) Darreann Carmela Hailey, MS, Bionano Genomics: Stocks/Bonds (Public Company)|Vaxart, Inc.: Stocks/Bonds (Public Company) Sean N. Tucker, PhD, Vaxart, Inc.: Grant/Research Support|Vaxart, Inc.: patent|Vaxart, Inc.: Ownership Interest|Vaxart, Inc.: Stocks/Bonds (Public Company) James F. Cummings, MD, VAXART: Stocks/Bonds (Public Company)

P-2060. Effectiveness of BNT162b2 COVID-19 Vaccination Against Long COVID Among Older Adults: A Nationwide Study

Abstract Background Long COVID includes new or persisting symptoms/signs/conditions impacting >1 organ/system following acute infection. The clinical presentation varies across patients and estimates of burden depend on the definition. Evidence on effectiveness of BNT162b2 BA.4/5 bivalent COVID-19 Vaccine (BNT162b2 bivalent) against long COVID remains scarce. This study assessed vaccine effectiveness (VE) of BNT162b2 bivalent for preventing long COVID symptoms among older adults.Table 1.Long COVID prevalence and vaccine effectiveness of BNT162b2 a against long COVID symptoms among older adults ≥50 years old Methods Symptomatic US adults ≥50 years old testing positive for SARS-CoV-2 via RT-PCR and rapid antigen at CVS Health were recruited between 03/02-05/18/2023 (CT.gov: NCT05160636). Participants reported presence or absence of each of 30 long COVID symptoms at 4 weeks, months 3 and 6 after testing. The CDC long COVID definition (new-onset or symptoms persisting ≥4 weeks after acute infection) was operationalized as the presence of ≥2 or ≥3 new or persistent symptoms consistent with long COVID from week 4 to month 6. The odds ratio (OR) of long COVID was computed for those who had received vs. had not received the BNT162b2 bivalent dose (vaccinated versus unvaccinated) before infection using mixed-effects logistic models, adjusting for multiple covariates. Absolute VE versus unvaccinated was calculated as (1‒OR)x100. Results Of 277 older adults aged ≥50 years recruited in the study, 172 received BNT162b2 and 105 did not. Mean time since last bivalent dose was 168 days. All study participants reported ≥1 long COVID symptoms through month 6. The prevalence of ≥2 and ≥3 long COVID symptoms at month 6 was 33.1% and 23%, respectively. Those who received the BNT162b2 bivalent dose were less likely than those who didn’t to report ≥2 symptoms (27.0% vs 44.4%; adjusted OR 0.50, 95% CI 0.28-0.88) and ≥3 symptoms (16.5% vs 34.9%; adjusted OR 0.43, 95% CI 0.24-0.79) from 4 weeks to 6 months since testing positive. Absolute VE ranged 50-57% (Table 1). Conclusion Despite high levels of immunity, especially among older adults, the post-pandemic burden of long COVID remains high, but is significantly lower for those vaccinated. Between 4 weeks and 6 months after testing positive, older adults vaccinated with BNT162b2 bivalent had approximately half the odds of long COVID than those unvaccinated. Disclosures Manuela Di Fusco, PhD, Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds (Public Company) Abby Rudolph, PhD, Pfizer Inc: Employer|Pfizer Inc: Stocks/Bonds (Public Company) Laura L. Lupton, MD, MHSA, CVS Health: Employee|CVS Health: Stocks/Bonds (Public Company) Joseph C. Cappelleri, PhD, Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds (Public Company) Alon Yehoshua, PharmD, MS, Pfizer Inc: Employer|Pfizer Inc: Stocks/Bonds (Public Company) Laura A. Puzniak, PhD. MPH, Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds (Public Company) Santiago M.C. Lopez, MD, Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds (Public Company) Xiaowu Sun, PhD, CVS Health: Employee|CVS Health: Stocks/Bonds (Public Company)

P-1101. A Comparative Analysis of Resistance Rates Among Escherichia coli and Klebsiella pneumoniae Isolates Collected from the Gepotidacin Uropathogen Global Surveillance Studies and Phase 3 Uncomplicated Urinary Tract Infection Clinical Studies

Abstract Background Gepotidacin (GEP) is a novel oral antibacterial under development for the treatment of uncomplicated urinary tract infection (uUTI) and gonorrhea. This study reports drug resistance rates for large collections of Escherichia coli (EC) and Klebsiella pneumoniae (KPN) isolates from the GEP uropathogen global surveillance studies vs isolates from 2 global GEP Phase 3 (Ph3) uUTI trials. Methods A total of (G [global]/US [a subset of global isolates from the United States]) 4481/2763 EC and 1769/1296 KPN isolates were collected from the GEP uropathogen global surveillance studies (2019–2022). From an unbiased collection of isolates from all enrolled participants with uUTI, a total of (G/US) 1159/609 EC and 114/80 KPN isolates were from the microbiological intent-to-treat population in the GEP uUTI Ph3 clinical studies. All isolates in both studies were cultured from urine collected from patients in outpatient settings. Isolate identification was confirmed by MALDI-TOF and susceptibility testing by CLSI methods was conducted at a central laboratory (JMI Laboratories [surveillance] and PPD GCL [clinical studies]). MICs for oral antibiotics used for the treatment of uUTI and drug-resistant subsets were interpreted per CLSI guidelines. Results EC: FQ-R rates were 18% and 31% for the US and 21% and 28% for G isolates from the surveillance and Ph3 studies respectively. Resistance rates for SXT and AMP were ≥ 27%; rates for AMC, NIT, FOS, and MEC were ≤ 4% for both studies. ESBL+ % range was 12–15% in both studies (Figure 1). KPN: Rates of FQ-R were similar for US (8%, 9%) and G isolates (14%,16%) from the surveillance and Ph3 studies respectively. Resistance rates for other antibacterials were 19–42% (NIT-R), 13–26% (SXT-R), and 8–16% (ESBL+ %) (Figure 2). Conclusion Drug resistance rates to many uUTI antibacterials tested were high in 1 or both studies for EC and KPN. GEP MIC90s were generally the same or 1 dilution higher than all isolates for resistant subsets of EC and KPN among both surveillance and Ph3 isolates (Table). Funding:Surveillance studies and EAGLE-2 were funded in part by GSK and in part with Federal funds from the US Office of the Assistant Secretary for Preparedness and Response, Biomedical Advanced Research and Development Authority (HHSO100201300011C). EAGLE-3 was funded by GSK. Disclosures Renuka Kapoor, PhD, GSK: Employee|GSK: Stocks/Bonds (Public Company) Deborah Butler, PharmD, GSK: Employee|GSK: Stocks/Bonds (Public Company) John Breton, MCM, GSK: Employee|GSK: Stocks/Bonds (Public Company) Cara Kasapidis, BS, GSK: Employee|GSK: Stocks/Bonds (Public Company) Derrek Brown, BS, GSK: A former agency worker at GSK Amanda Sheets, PhD, GSK: Employee|GSK: Stocks/Bonds (Public Company) Didem Torumkuney, PhD, GSK: Employee|GSK: Stocks/Bonds (Public Company) S.J. Ryan Arends, PhD, JMI: SJRA is an employee of JMI. JMI was contracted by and received financial support from GSK to conduct gepotid Rodrigo E. Mendes, PhD, JMI: RM is an employee of JMI. JMI was contracted by and received financial support from GSK to conduct gepotidac|Paratek Pharmaceuticals: Advisor/Consultant|Paratek Pharmaceuticals: Grant/Research Support Nicole E. Scangarella-Oman, MS, GSK: Employee|GSK: Stocks/Bonds (Public Company)

P-658. Cost-Effectiveness of V116, an Adult Specific 21-Valent Pneumococcal Conjugate Vaccine, vs. PCV20 on Pneumococcal Disease in Japan--A Delta-Price Approach

Abstract Background V116 is an investigational 21-valent pneumococcal conjugate vaccine (PCV) specifically designed for adults. It includes eight unique serotypes (15A, 15C [generated from deOAc-15B], 16F, 23A, 23B, 24F, 31 and 35B) not covered by any currently licensed pneumococcal vaccine (Figure 1). This study used the delta-price approach to conduct a cost-effectiveness analysis (CEA) of vaccinating adults aged 65+ years with V116 vs. PCV20 in Japan. Methods A Markov model was built to track the lifetime health and economic outcomes of using V116 compared to PCV20 among adults in Japan. The same vaccine effectiveness values were assumed for the two vaccines. We assumed a vaccination coverage rate of 39% based on current Japanese reports of vaccination rates in 65-year-olds. Costs were adjusted to 2024 JPY and a 2% discount rate for both costs and quality-adjusted life-years (QALYs) were used to perform the CEA. The CEA was conducted from societal (direct and indirect costs included) and health care (only direct costs) perspectives. A premium price (price difference vs. PCV20) was used in the analysis. The summary results were presented as incremental cost-effectiveness ratios (ICERs). Results Vaccinating 39% of adults aged 65+ years with V116 prevented approximately 113,000 total cases of pneumococcal disease (PD) and 6,700 disease-related deaths; meanwhile PCV20 prevented approximately 91,000 total cases of PD and 5,400 disease-related deaths (Table 1). When compared to PCV20, V116 yielded an additional 8,500 QALYs, reduced medical costs by 17.15 billion JPY, and reduced indirect costs by 5.68 billion JPY. V116 was cost-saving up to a premium price of 1,213 JPY and 1,615 JPY from the health care and societal perspectives, respectively. At an ICER of 5 million JPY/QALY gained, V116 was cost-effective up to a premium price of 4,210 JPY and 4,612 JPY from the health care and societal perspectives, respectively (Figure 2). Model outcomes were most sensitive to discount rates and medical costs for NBPP (Figure 3). Conclusion At a premium price between 4,210 and 4,612 JPY, V116 remained cost-effective when compared to PCV20 in Japanese adults 65+ years; and a premium price between 1,213 and 1,615 JPY was found to be cost-saving for the same strategy comparison. Disclosures Peter P. Mueller, PhD, Merck & Co. Inc.: Stocks/Bonds (Public Company) Atsushi Tajima, n/a, Merck & Co. Inc.: Stocks/Bonds (Public Company)|MSD: Employee Taizo Matsuki, n/a, GSK: Past employee by October 2023|MSD: Study and publication fund|MSD: Stocks/Bonds (Public Company) Nicole Cossrow, PhD, Merck: Stocks/Bonds (Public Company) Zinan Yi, n/a, Merck: Stocks/Bonds (Public Company) Kelly D. Johnson, PhD, Merck & Co., Inc.: Employee|Merck & Co., Inc.: Stocks/Bonds (Public Company) Kwame Owusu-Edusei, Ph.D., Merck & Co., Inc., Rahway, NJ, USA: Employee|Merck & Co., Inc., Rahway, NJ, USA: Stocks/Bonds (Public Company)

P-617. Estimating Pediatric Breakthrough Disease from Pneumococcal Vaccines in France

Abstract Background In France, effective pneumococcal conjugate vaccines (PCVs) and the high vaccine coverage rate (VCR) of 95% have led to a substantial decline in pediatric invasive pneumococcal disease (IPD) incidence. PCV13 is currently used in a 2+1 dosing regimen; PCV15 and PCV20 are expected to be introduced soon. Breakthrough IPD (bIPD), defined as fully vaccinated individuals who develop vaccine type IPD, persists for some PCV13 serotypes (STs). As ST-specific immune responses decrease with increased PCV valency, understanding the potential impact of PCV15 and PCV20 on PCV13 STs bIPD is important. IPD Breakthrough disease incidence per 100,000 children under two years of age. Methods We evaluated the expected impact of PCV15 in a 2+1 regimen, or PCV20 in either a 2+1 or 3+1 regimen on PCV13 ST bIPD incidence in children < 2 years of age over 5 and 10 years using a compartmental dynamic transmission model. The model incorporated historical PCV introductions and calibrated age- and ST-specific IPD data spanning 2000-2019. Predicted ST-specific vaccine effectiveness (VE) for PCV15 and PCV20 were used1,2. Incidence of bIPD was evaluated across 3 ST groupings: PCV7 STs, PCV13-non-ST3 STs, and ST3. VCRs were maintained at 95% in the model. Results were compared to 2019 IPD incidence. Results Using previously published ST-specific VE predictions, routine use of PCV15 in children led to fewer PCV13 ST bIPD cases than use of PCV20. PCV15 reduced bIPD incidence in all 3 ST groups (-30% to -87%, Table 1). The introduction of PCV20 in a 2+1 or 3+1 regimen resulted in more bIPD cases from PCV7 and PCV13-non-ST3 STs. ST3 bIPD was maintained at current levels in a 2+1 regimen but decreased with PCV20 in a 3+1 regimen. Conclusion Using published predicted VEs, implementation of PCV20 in a 2+1 or 3+1 regimen led to a substantial increase in bIPD incidence of PCV7 and PCV13 non-ST3 STs relative to currently used PCV13 2+1 regimen. PCV15 in a 2+1 regimen reduced bIPD incidence across all ST groups, with the largest impact on ST3. As higher-valent PCVs are introduced, the impact of their reduced ST-specific immune responses, and therefore lower predicted VE on pediatric PCV13 STs, should be weighed against the benefits of additional ST coverage. 1Ryman J, et al. Expert Rev Vaccines. 2024;23(1):60-68. 2Ryman J, et al. Expert Rev Vaccines. 2024;23(1):467-473. Disclosures Kevin Bakker, PhD, Merck & Co., Inc.: Grant/Research Support|Merck & Co., Inc.: Stocks/Bonds (Public Company) Rachel Oidtman, PhD, Merck & Co., Inc.: Full time employee|Merck & Co., Inc.: Stocks/Bonds (Public Company) Giulio Meleleo, PhD, Merck & Co., Inc.: Vendor Priscilla Velentgas, PhD, Merck & Co., Inc., Rahway, NJ, USA: Grant/Research Support|Merck & Co., Inc., Rahway, NJ, USA: Stocks/Bonds (Public Company) Kenneth Klinker, PharmD, Merck & Co., Inc., Rahway, NJ, USA: Grant/Research Support|Merck & Co., Inc., Rahway, NJ, USA: Stocks/Bonds (Public Company) Natalie Banniettis, MD, Merck & Co., Inc., Rahway, NJ, USA: Grant/Research Support|Merck & Co., Inc., Rahway, NJ, USA: Stocks/Bonds (Public Company) Kristen A. Feemster, MD, MPH, MSHPR, FAAP, Merck & Co., Inc., Rahway, NJ, USA: Grant/Research Support|Merck & Co., Inc., Rahway, NJ, USA: Stocks/Bonds (Public Company) Jessica Weaver, PhD, MPH, Merck & Co. Inc.: Employment|Merck & Co. Inc.: Stocks/Bonds (Public Company)

P-1546. Discordant Clinical and Microbiological Responses are Associated with Late Clinical Relapse in Uncomplicated Urinary Tract Infections: Pooled Analysis of EAGLE-2/EAGLE-3 Trial Data

Abstract Background Regulatory guidance recommends the primary endpoint for uncomplicated urinary tract infection (uUTI) trials be a composite of clinical and microbiological response. However, discordant outcomes have raised questions regarding the clinical utility of the microbiological component. The aim of this post hoc analysis was to explore the clinical significance of the microbiological endpoint based on pooled data from two recent Phase 3 trials in uUTI (EAGLE-2 [NCT04020341]/-3 [NCT04187144]). Methods EAGLE-2/-3 compared gepotidacin (1500mg) to nitrofurantoin (NTF; 100mg), both twice daily for 5 days in females aged ≥ 12 years with uUTI. Combined clinical success (CS) and microbiological success (MS) at test-of-cure (TOC) (days 10–13) was defined as quantified complete uUTI symptom resolution with no new symptoms and reduction of baseline qualifying uropathogens from ≥ 105 to < 103 CFU/mL, without other systemic antibiotic use. Pooled trial data with treatment groups combined were used to assess if discordant clinical and microbiologic responses at TOC impacted clinical responses at follow-up (FU; day 28±3). Results In total, 1201 patients were included in the pooled population; 90% had Escherichia coli and 40% had history of recurrence. Overall, 22% of patients with discordant responses at TOC (CS + microbiological failure [MF]) became clinical failure (CF) at FU compared with 14% of patients with concordant success (CS + MS; Figure). The odds ratio of CF at FU for those with discordant vs concordant responses was 1.7 (95% confidence interval: 1.1–2.6, adjusted for study effect; p=0.012). Results were similar when the analysis was conducted excluding patients with missing data and protocol non-adherence (Figure). Conclusion Discordant responses (CS + MF) at TOC were associated with increased risk of CF (relapse) at FU in this post hoc analysis. Based on the results of pooled EAGLE-2/-3 data, microbiological response appears to be an important component of treatment success criteria in uUTI trials and may predict clinical relapse. Funding EAGLE-2 was funded in part by GSK and in part with Federal funds from the US Office of the Assistant Secretary for Preparedness and Response, Biomedical Advanced Research and Development Authority (HHSO100201300011C). EAGLE-3 was funded by GSK. Disclosures Amanda Sheets, PhD, GSK: Employee|GSK: Stocks/Bonds (Public Company) Judith Absalon, MD, GSK: Employee|GSK: Stocks/Bonds (Public Company) Jeremy Dennison, MD PhD, GSK: Employee|GSK: Stocks/Bonds (Public Company) Caroline R. Perry, PhD, GSK: Employee|GSK: Stocks/Bonds (Public Company) Nicole E. Scangarella-Oman, MS, GSK: Employee|GSK: Stocks/Bonds (Public Company) Helen Millns, PhD, GSK: Employee|GSK: Stocks/Bonds (Public Company) Salim Janmohamed, MD, GSK: Employee|GSK: Stocks/Bonds (Public Company)

512. Efficacy of Gepotidacin versus Nitrofurantoin in a Nitrofurantoin Not Susceptible Population: A Pooled Analysis of the EAGLE-2 and EAGLE-3 Randomized Controlled Trials in Uncomplicated Urinary Tract Infection

Abstract Background Two Phase 3 trials (EAGLE-2 [NCT04020341]/EAGLE-3 [NCT04187144]) showed that gepotidacin, a first-in-class triazaacenaphthylene antibacterial, was non-inferior to nitrofurantoin (NTF) in treating uncomplicated urinary tract infection (uUTI) caused by NTF-susceptible (NTF-S) qualifying uropathogens (≥ 105 CFU/mL).1 This study evaluates gepotidacin efficacy in the pooled EAGLE-2/3 microbiological intent-to-treat (micro-ITT) NTF not susceptible (NTF-NS) population. Methods In EAGLE-2/3, female patients aged ≥ 12 years with ≥ 2 uUTI symptoms received oral gepotidacin (1500mg) or NTF (100mg) twice-daily for 5 days.1 In this study, therapeutic, clinical and microbiological response (defined in tables) at test-of-cure (Day 10–13) were assessed in the pooled EAGLE-2/3 micro-ITT NTF-NS and NTF-S populations and across patient subgroups. Results Of the 1421 micro-ITT patients, 220 (15%) had NTF-NS uropathogens and 1201 (85%) had NTF-S uropathogens. The most common baseline uropathogens were Escherichia coli (90%) in the NTF-S population, and Klebsiella pneumoniae (31%), Proteus mirabilis (26%), and E. coli (24%) in the NTF-NS population (Table 1). Across key subgroups, the proportion of patients with NTF-NS uropathogens was broadly similar to the overall population (except Hispanic/Latinx, Black race and US subgroups which were numerically higher; Figure 1). For efficacy outcomes, treatment differences were higher in the NTF-NS vs the NTF-S population, and, as expected, favored gepotidacin vs NTF (Table 2). Treatment differences in therapeutic success were numerically higher across key subgroups in the NTF-NS vs the NTF-S population (Figure 2). Conclusion Gepotidacin was efficacious in both populations, and across subgroups, with a higher therapeutic treatment difference in the NTF-NS vs the NTF-S population. Gepotidacin could offer benefit in patients with uUTI, including those with NTF-NS uropathogens. 1. Wagenlehner F, et al. Lancet 2024;403:741–55. Funding: EAGLE-2 was funded in part by GSK and in part with Federal funds from the US Office of the Assistant Secretary for Preparedness and Response, Biomedical Advanced Research and Development Authority (HHSO100201300011C). EAGLE-3 was funded by GSK. Disclosures Jeremy Dennison, MD PhD, GSK: Employee|GSK: Stocks/Bonds (Public Company) Amanda Sheets, PhD, GSK: Employee|GSK: Stocks/Bonds (Public Company) Sarah Watts, MSc, GSK: Employee|GSK: Stocks/Bonds (Public Company) Nicole E. Scangarella-Oman, MS, GSK: Employee|GSK: Stocks/Bonds (Public Company) Deborah Butler, PharmD, GSK: Employee|GSK: Stocks/Bonds (Public Company) John Breton, MCM, GSK: Employee|GSK: Stocks/Bonds (Public Company) Salim Janmohamed, MD, GSK: Employee|GSK: Stocks/Bonds (Public Company)

P-2054. Effectiveness of a Single COVID-19 mRNA Vaccine Dose in Individuals Previously Infected with SARS-CoV-2: A Systematic Review

Abstract Background Based on the high levels of population immunity to SARS-CoV-2 from prior infection in many countries, in fall 2023 the US Food and Drug Administration, European Medicines Agency, and World Health Organization authorized/recommended a single mRNA XBB.1.5-adapted vaccine dose for unvaccinated individuals aged ≥ 5y. Methods This systematic literature review evaluated the vaccine effectiveness (VE) of a single COVID-19 mRNA dose (BNT162b2 or mRNA-1273) in individuals previously infected with SARS-CoV-2 compared to those with differing histories of prior infection and vaccination (PROSPERO ID: CRD42023453257). We searched MEDLINE and Embase for VE studies published from January 1, 2021–October 4, 2023. Data were synthesized following Synthesis Without Meta-Analysis guidelines. Bias was assessed using the Newcastle-Ottawa Scale. VE estimates were reported as a range of point estimates per clinical endpoint and meta-analyses were not performed due to heterogeneity. Results Of 1,661 initial results, 18 studies were eligible for inclusion. Among those previously infected, a single mRNA dose (compared to being unvaccinated) increased protection by 8–71% against infection (related to Omicron BA.1, BA.4/5, or XBB), 39–67% against symptomatic infection (BA.1, BA.2, or BA.4/5), and 25–60% against hospitalization or hospitalization or death (BA.1). The protection provided by a single dose among those previously infected was comparable to the VE provided by two doses, and was higher than VE following two doses without prior infection. No studies were identified that reported single-dose VE for adapted vaccines (BA.1 or BA.4/5 bivalent or XBB.1.5-adapted formulations), immunocompromised populations, or children aged < 5y. Conclusion Our results suggest that a single dose of COVID-19 vaccine provides similar protection to that conferred by a two-dose series for immunocompetent individuals aged ≥ 5y in the current setting of high pre-existing SARS-CoV-2 immunity. These findings support current recommendations for one dose of COVID-19 vaccines regardless of vaccination status to be given in advance of the viral respiratory season with considerations for additional doses for certain special populations including young children, older adults, and the immunocompromised. Disclosures Hannah R. Volkman, PhD, MPH, Pfizer Inc: Employment|Pfizer Inc: Stocks/Bonds (Public Company) Jennifer L Nguyen, ScD, MPH, Pfizer Inc: Employment|Pfizer Inc: Stocks/Bonds (Public Company) Mustapha M. Mustapha, MD, PhD, MPH, Pfizer Inc: Employment|Pfizer Inc: Stocks/Bonds (Public Company) Jingyan Yang, MHS, DrPH, Pfizer Inc: Employment|Pfizer Inc: Stocks/Bonds (Public Company) Luis Jodar, PhD, Pfizer Inc: Employment|Pfizer Inc: Stocks/Bonds (Public Company) John M. McLaughlin, PhD, Pfizer: Employee|Pfizer: Stocks/Bonds (Public Company)

P-629. The Health and Economic Impact of the PCV15 and PCV20 Priming Series during the First Year of Life in the US

Abstract Background Two pneumococcal conjugate vaccines, 15- (PCV15) and 20- (PCV20) valent formulations, are currently recommended for US infants in a 3+1 schedule. The first 3 doses are administered during the first year of life (‘priming doses’ at 2, 4, and 6 months) while the booster dose is given at 12 to 15 months. This study evaluated the health and economic impact of priming doses within the first year of life. Methods Using a decision-analytic model, we calculated the health outcomes and economic implications from a healthcare payer perspective over a 12-month duration. Our epidemiological data were drawn from peer-reviewed studies. Estimates for vaccine effectiveness on invasive pneumococcal disease (IPD), inpatient and outpatient community-acquired pneumonia (CAP), and otitis media (OM) were extrapolated from established PCV13 effectiveness and PCV7 efficacy studies and adjusted for current serotype coverage of PCV15 and PCV20. Direct medical costs related to the treatment of IPD, CAP and OM were extracted from the literature and inflated to 2024 dollars. Aligned with CDC assumptions, we projected that children would experience 75.6% of the full vaccine effectiveness in their first year of life. Results Vaccination of newborns in the United States at 2, 4, and 6 months using PCV20 could potentially prevent an estimated 137 cases of IIPD, 3,150 cases of pneumonia, 54,000 cases of OM, and 38 deaths during the first year of life. This could result in savings of approximately 76M dollars in direct medical costs. When compared to universal administration of PCV15, PCV20 offers greater case prevention due to its broader serotype coverage. Specifically, using PCV15 instead of PCV20 would result in 54 fewer prevented cases of IPD, 26,200 fewer cases of otitis media, 1,526 fewer pneumonia cases, and 16 fewer prevented deaths. Conclusion This study showed that, in the US, vaccinating with PCV20 would yield a significantly greater health and economic return during the first 12 months of life compared to PCV15 due to the 5 additional serotypes covered by PCV20. Disclosures Mark Rozenbaum, PhD, M.B.A., Pfizer: Stocks/Bonds (Public Company) Benjamin Althouse, PhD, Pfizer: Stocks/Bonds (Public Company) Maria J. Tort, PhD, Pfizer Inc: Stocks/Bonds (Public Company) Alejandro D. Cane, MD, PhD, Pfizer: Employee|Pfizer: Stocks/Bonds (Public Company)|Pfizer: Stocks/Bonds (Public Company) Raymond Farkouh, PhD, Pfizer: Stocks/Bonds (Public Company)

P-2017. Patient Reported Outcomes of Nirmatrelvir/Ritonavir Treatment for High-risk, Nonhospitalized Adults with Symptomatic COVID-19

Abstract Background Nirmatrelvir/ritonavir (NMV/r) is an oral antiviral treatment for coronavirus disease 2019 (COVID-19). We describe patient-reported outcomes (PROs) with NMV/r in nonhospitalized adults with COVID-19 at high risk of severe disease. Percentage of participants in each treatment group in the mITT2 population reporting return to usual health on each study day through Day 28 on the Global Impressions Questionnaire. n=number of patients with event; mITT2=modified intent-to-treat 2; N=number of patients with nonmissing data. CI=confidence interval; HR=hazard ratio Methods In a phase 2/3 double-blind study, high-risk adults with confirmed COVID-19 and ≤ 5 days of symptoms were randomized 1:1 to receive NMV/r or placebo twice daily for 5 days. All PRO analyses included participants randomly assigned to a study intervention who received ≥ 1 dose of the study intervention and had ≥ 1 postbaseline visit through Day 28 (modified intent-to-treat 2 [mITT2] population). Patients recorded responses to three Global Impression Questions (GIQ) daily through Day 28 to assess return to usual health, return to usual activities, and overall severity of COVID-19 related symptoms. COVID-19–specific Work Productivity and Activity Impairment Questionnaire (WPAI-COVID-19), and the EuroQol Quality of Life 5-Dimension 5-Level Scale (EQ-5D-5L) were completed at specified visits through Week 24. Percentage of participants in each treatment group in the mITT2 population reporting return to usual activities on each study day through Day 28 on the Global Impressions Questionnaire. n=number of patients with event; N=number of patients with nonmissing data. CI=confidence interval; HR=hazard ratio; mITT2=modified intent-to-treat 2 Results Compared with placebo, patients receiving NMV/r had a significant 3-day reduction in median time to return to usual health (hazard ratio [HR], 1.3; 95% confidence interval [CI], 1.2–1.4), 1-day reduction in median time to return to usual activities (HR, 1.2; 95% CI, 1.1–1.4), and significantly shorter time to sustained resolution of any overall symptoms (HR, 1.2; 95% CI, 1.1–1.3) and sustained alleviation of any overall symptoms (HR, 1.2; 95% CI, 1.1–1.3) based on the GIQ. There were no significant differences between treatment groups on the WPAI or EQ-5D-5L. Conclusion High risk patients receiving NMV/r for COVID-19 reported a reduced duration and severity of COVID-19 symptoms based on their global impression of overall symptom burden and quicker return to usual heath and usual activities compared with those receiving placebo. The main limitation of this analysis was the lack of sufficient ePRO data collection of WPAI and EQ-5D-5L questionnaires. As such, no meaningful conclusions could be drawn regarding the impact of NMV/r on work productivity or activity impairment of HRQoL. Disclosures Ashley S. Cha-Silva, PharmD, MS, Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds (Public Company) Jinma Ren, PhD, Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds (Public Company) Amie Scott, MPH, Pfizer: Employee|Pfizer: Stocks/Bonds (Public Company) Joseph C. Cappelleri, PhD, Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds (Public Company) Wajeeha Ansari, MPH, Pfizer: Employee|Pfizer: Stocks/Bonds (Public Company) Heidi Leister-Tebbe, BSN, Pfizer: Employee|Pfizer: Stocks/Bonds (Public Company)

P-2062. COVID-19 XBB.1.5-adapted Vaccine Uptake in Immunocompromised Individuals Using Tokenized State Vaccine Registries

Abstract Background Immunocompromised individuals experience a disproportionate burden of COVID-19-associated hospitalization and death. COVID-19 vaccine uptake has declined over time. We evaluated XBB.1.5-adapted vaccine uptake, regardless of brand, during the 2023-2024 season among immunocompromised persons using data from two large state vaccine registries. Methods Individuals with continuous pharmacy and medical enrollment (≥6 months for children < 18 years, ≥12 months for adults ≥18 years) in insurance plans contributing to HealthVerity and residency in either California or Louisiana as of September 11, 2023 (the date XBB.1.5-adapted vaccines were authorized or approved) were selected. A prior dose of any COVID-19 vaccine was required. Persons were defined as immunocompromised if they had one or more of the following conditions as defined by the Centers for Disease Control and Prevention: HIV/AIDS, hematologic malignancy, solid organ or bone marrow transplant, primary immunodeficiency, or recent use of immunosuppressive medications. XBB.1.5-adapted vaccine uptake was assessed using de-identified records from state vaccine registries in California and Louisiana that were linked via tokenization with claims data. Results A total of 321,896 California residents (median age 55 years; 57% female) and 43,250 Louisiana residents (median age 45 years; 64% female) with at least one immunocompromising condition were identified. In both states, the most common immunocompromising condition was use of immunosuppressive medications (78% California and 85% Louisiana). By the end of March 2024, 19% and 6% of immunocompromised individuals in California and Louisiana, respectively, received an XBB.1.5-adapted vaccine. Uptake was generally similar regardless of immunocompromising condition (Table 1). Conclusion During the 2023-2024 season, COVID-19 vaccine uptake in immunocompromised persons was low, with fewer than 20% of this high-risk population receiving the XBB.1.5-adapted vaccine. Enhanced efforts to increase COVID-19 vaccine uptake in this vulnerable population are urgently needed. Disclosures Matthew A. Brouillette, MPH, Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds (Public Company) Farid L. Khan, MPH, Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds (Public Company) Santiago M.C. Lopez, MD, Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds (Public Company) Kathleen M. Andersen, PhD MSc, Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds (Public Company) Tiange Yu, MS, Pfizer Inc.: Employee of Genesis Research Group which has received consulting fees from Pfizer Inc. Benjamin T. Carter, PhD, Pfizer Inc.: Employee of Genesis Research Group which has received consulting fees from Pfizer Inc. John M. McLaughlin, PhD, Pfizer: Employee|Pfizer: Stocks/Bonds (Public Company) Leah McGrath, PhD, Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds (Public Company)