COVID-19 Research Articles

426. Effectiveness of Updated (2023-2024) Monovalent COVID-19 Vaccines – VISION Network, September 2023-March 2024

Abstract Background In September 2023, the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices (ACIP) recommended updated 2023-2024 (monovalent XBB.1.5) COVID-19 vaccines for use in persons ≥6 months for prevention of COVID-19, including severe disease. Understanding how well updated COVID-19 vaccines work in the context of high population immunity due to prior infection, vaccination, or both, is important for future vaccine policy decisions, as well as informing patient/provider discussions, and increasing vaccine confidence. Effectiveness of updated (2023-2024) COVID-19 vaccination against laboratory-confirmed COVID-19-associated emergency department/urgent care encounters and hospitalization among immunocompetent adults aged ≥18 years — VISION Network, September 2023–March 2024 Methods VISION, an electronic health record (EHR)-based network including emergency departments/urgent care clinics (ED/UCs) and hospitals including 6 health systems, uses clinician-ordered testing data to estimate vaccine effectiveness (VE) for respiratory viruses. COVID-19 VE was estimated using the test-negative design, comparing the odds of vaccination with a single updated 2023-2024 COVID-19 vaccine dose between patients who tested positive versus those who tested negative for SARS-CoV-2 by molecular assay, adjusting for potential confounders. Effectiveness of updated 2023–2024 (monovalent XBB.1.5) COVID-19 vaccination against laboratory-confirmed COVID-19–associated hospitalization among immunocompromised adults aged ≥18 years — VISION network, September 2023–March 2024 Results A total of 198,345 ED/UC encounters and 59,777 hospitalizations between September 2023-March 2024 among immunocompetent adults ≥18 years with symptoms of COVID-19 were included. VE against COVID-19-associated ED/UC encounters comparing receipt of an updated dose to no receipt of an updated dose was 50% (95% CI: 46-53%) in the 7-59 days and 0 (95% CI: -14 to 12) in the 120-179 days after receipt of an updated dose (Table 1). VE against COVID-19-associated hospitalization was 50% (95% CI: 44-56%) in the 7-59 days and 23 (95% CI: 2-39) in the 120-179 days after receipt of an updated dose (Table 1). A total of 17,417 hospitalizations among immunocompromised adults ≥18 years with symptoms of COVID-19 were included, with a VE of 38% (95% CI: 23-50%) in the 7-59 days and 14 (95% CI: -33 to 44) in the 120-179 days after receipt of an updated dose after an updated dose (Table 2). Conclusion Receipt of an updated COVID-19 vaccine dose provided protection against COVID-19-associated ED/UC encounters and hospitalizations among immunocompetent and immunocompromised adults, although waning was evident. Disclosures Nicola P. Klein, MD, PhD, GlaxoSmithKline: Grant/Research Support|Merck: Grant/Research Support|Pfizer: Grant/Research Support|Sanofi Pasteur: Grant/Research Support|Seqirus: Grant/Research Support Toan Ong, PhD, Patent Title: Systems and Methods For Record Linkage: PCT/US2018/047961 Patent Title: Systems and Methods For Record Linkage|PCORI: Travel support to attend the PCORI Annual meeting in Washington DC, 2023|Regenstrief Institute: Advisor/Consultant|Regenstrief Institute: Travel support to attend the OHIE 23 meeting in Malawi. Brian E. Dixon, PhD, Elsevier: Honoraria

P-1931. Health-related quality of life one year after mild COVID-19 infection: a multicenter prospective cohort study

P-1931. Health-related quality of life one year after mild COVID-19 infection: a multicenter prospective cohort study

P-2066. Impact of XXB 1.5 Monovalent Booster Vaccination on Mucosal and Systemic Immune Responses in Healthy Adults

Abstract Background The FDA recently approved the first monovalent XBB1.5 booster vaccine. However, the mechanism by which this vaccine stimulates mucosal and systemic immune responses has been understudied.Figure 1.Impact of XBB 1.5 vaccination on viral neutralization titers using pseudo virus assay (left panel) and ACE2 inhibition assay (right panel).Each dot (white) represents a single serum sample tested in parallel with a post-vaccination sample (colored dot) for each of the 28 participants. The mean fold increase in neutralization titers pre- and post-vaccination are shown for Wuhan, XBB 1.5, and BA5 variants. All increases in neutralization titers are significant to P<0.0001 by employing Wilcoxon matched-pairs signed rank test. Methods We examined 28 participants' serum and saliva one week before and two to three weeks after the XBB1.5 mRNA vaccination for neutralizing and binding antibodies to Wuhan and XBB1.5 S protein.Figure 2:Inhibition of ACE2 binding to different S variants by saliva samples pre- and post-vaccination with XBB1.5 monovalent booster.Paired samples represent the percent ACE2 binding inhibition in participants before and after vaccination. Vaccination induced a 1.7-fold increase in ACE2 neutralization in saliva to XBB1.5 (p<0.0001) and 1.2-fold increase in ACE2 neutralization to Wuhan (p=0.03). Significance tested between pre and post-vaccination by Wilcoxon matched-paired sign rank test. *** p<0.001, **** p<0.0001. Results We observed a 2.9 to 2.6-fold and 5.0 to 7.8-fold increase in Wuhan and XBB1.5 serum neutralization titers following mRNA vaccination using pseudovirus and ACE2 neutralization assays respectively, that closely correlated with a rise in binding antibodies to S protein. Vaccination induced a 1.7-fold increase in ACE2 neutralization in saliva to XBB1.5 (p< 0.0001) and 1.2-fold increase in ACE2 neutralization to Wuhan (p=0.03). This increase in neutralization Ab levels in saliva failed to correlate with the number and time of prior COVID-19 infections, vaccination status, type of vaccine, or concomitant rise in S-specific IgA or IgG in saliva or serum. Depletion of IgA or IgG in saliva following vaccination demonstrated that IgA was primarily responsible for the increase in ACE2 blocking activity (mean reduction in blocking activity with IgA depletion=68%, range, 58-81%) compared to IgG (mean reduction=27%, range 0-71%).Figure 3.Role of IgA on percent reduction in ACE2 inhibition in saliva. Depletion of IgA or IgG in saliva following vaccination demonstrated that IgA was primarily responsible for the increase in ACE2 blocking activity (mean reduction in blocking activity with IgA depletion=68%, range, 58-81%) compared to IgG (mean reduction=27%, range 0-71%). Statistical analysis done using unpaired t test. Conclusion The XBB1.5 monovalent vaccine boosts systemic and mucosal viral neutralization antibody levels, primarily to the XBB1.5 variant. Most people have hybrid immunity to SARS-CoV2 now, so mRNA vaccines boost mucosal immune response better than observed earlier in the pandemic. Increased oral mucosal immunity may reduce the risk of COVID-19 progressing to pneumonia and more severe disease. Disclosures All Authors: No reported disclosures

Gidoodikosan Giiwitaabimin - We sit in a circle for kidneys, a strength-based qualitative study.

Abstract The overall aim of this qualitative study was to inform recommendations towards Indigenous strength-based approaches for kidney health, prevention of disease and failure. Between 2020 and 2022, during the COVID-19 pandemic, we conducted online interviews and teleconferences with 16 participants from North Simcoe in Ontario, Canada. Participants shared their experiences revolving around kidney disease and care within Indigenous contexts. An advisory committee consisting of members from a First Nation community with personal and familial experiences with kidney disease provided direction to the research in conjunction with the research team. Analysis occurred through the collective consensual data analytic procedure (CCDAP) consistent with a strength-based methodology that involved the coming together of community members with the research team. Themes were identified into groupings that led to the recommendations related to (1) health care continuity of traditional and cultural ways of knowing and being; (2) accessible hemodialysis and support for home dialysis; (3) increased kidney transplantation and kidney organ donation, (4) increased telehealth and virtual medicine; and (5) government support and funding. Accessible culturally safe care within home communities that also serves to limit the spread of COVID-19 infection was prioritized.

P-2065. Profile and Risk Factors of Breakthrough COVID-19 Infections Among Healthcare Workers Post-Vaccination

Abstract Background This study aimed to assess breakthrough COVID-19 infections in vaccinated healthcare workers, characterize their demographic and clinical profiles and identify associated risk factors. Methods A cross-sectional study was conducted in four hospitals using a stratified sampling approach. Data were collected via standardized questionnaires and analyzed using descriptive statistics for demographic and clinical features, with Chi-square or Fisher’s exact test to examine for significant associations and T-tests or Mann-Whitney U Tests for significant differences. Results Among 378 vaccinated healthcare workers, all experienced breakthrough infections, the majority during the surge of the omicron variant. Overall, 60% were females, and 91.5% were below 44. There were 172 (45.5%) nurses, 66 (17.5%) physicians, and the remaining were paramedical personnel. Breakthrough infections were shorter in vaccinated individuals (mean 11 days, SD = 5.58) compared to unvaccinated (mean 14 days, SD = 8.11). For those who developed their first breakthrough infection, the need for hospitalization and abnormal clinical and laboratory findings were significantly lower compared to unvaccinated. Among the vaccinated, higher rates of first breakthrough infection were significantly associated with being healthcare-associated and part of an outbreak. During the surge of infections due to the omicron variant, community-associated exposure and hospitalization were significantly higher among unvaccinated patients. Healthcare-associated contact was significantly associated with vaccinated people. By regression analysis, breakthrough infections due to omicron were significantly associated with a higher number of vaccine doses (OR 4.465 95% CI 1.978, 10.083) and hospitalization (OR 11.2 95% CI 2.386, 52.728). The probability of contracting the omicron variant with unknown exposure in patient care units within the past 14 days is lower (OR 0.389, 95% CI 0.174-0.866). Conclusion Breakthrough COVID-19 infections occurred in all vaccinated healthcare personnel, with new variants and healthcare-related duties playing significant roles. Disclosures All Authors: No reported disclosures

P-1900. Temporal Course and Risk Factors of Coinfections in Patients Hospitalized for COVID-19

Abstract Background Studies about the distinction between coinfections acquired prior to admission and hospital-acquired coinfections and risk factors at different time point are limited. Methods We reviewed microbiology laboratory data of patients hospitalized for COVID-19 viral infection during January 1, 2024 to March 13, 2024. Results We collected data on 75 patients. The temporal course of coinfection rate was: 9.3% on the same day of hospital admission (Day 1); 10.7% on Day 2 to Day 4; 2.7% on Day 5 to Day 9; 14.7% after Day 9 . At any time point prior to or during the hospitalization or rehospitalization, 23 (30.7%) patients acquired infection of at least one organism. Univariate analysis showed younger age (69 years vs. 78 years, p=0.025), lower proportion of diabetic patients (17.4% vs. 44.2%, p=0.036), lower proportion of chronic kidney disease (17.4% vs. 40.4%, p=0.065), higher proportion of indwelling catheter (17.4% vs. 1.9%, p=0.029), higher proportion of cancer (34.8% vs.13.5%, p=0.057), similar prior antibiotics (43.5% vs. 36.5%, p=0.6), and significant higher proportion of prior corticosteroids (21.7% vs. 3.9%, p=0.025) in coinfected group than not-coinfected group. Multivariate analysis indicated that indwelling catheter at baseline (OR=45.8, 95%CI: 3.2-652.8, p=0.005) and prior corticosteroids (OR=17.1, 95%CI: 0.99-296.4, p=0.051) are the two independent risk factors for coinfection at admission. Younger age (OR=0.96, 95%CI: 0.918-1.000, p=0.0495) and prior corticosteroids (OR=52.6, 95%CI: 3.11-891.3, p=0.006) are the two independent risk factors for hospital-acquired coinfection. Conclusion About 10% of patients hospitalized for COVID-19 infection had coinfection(s) at admission, with Escherichia coli being the most common. The coinfections at admission were eradicated within eight days. The second wave of coinfection(s) acquired during hospitalization rose to about 15% after eight days, with Klebsiella being the most common. Patients with indwelling catheter or prior corticosteroids use are in much greater risk to be coinfected with COVID-19 before hospital admission. Patients with prior corticosteroids are at fifty-time higher risk for hospital-acquired coinfections. Disclosures All Authors: No reported disclosures

P-202. 7- Year experience with Clostridioides difficile Infection (CDI): pre- and post-COVID-19 pandemic, effect of diagnostic stewardship and the gender difference

Abstract Background Diagnostic stewardship interventions, such as order sets, reflex orders, hard and soft stop alerts and decision algorithms have shown to improve facility C. difficile rates. We aimed to examine the impact of COVID-19 infection and diagnostic stewardship on incidence and prevalence of CDI at our institution, based on gender. Methods Using National Healthcare Safety Network (NHSN) surveillance Laboratory Identification (Lab ID) events, 926 CDI cases, ≥ 18 years of age were identified among patients hospitalized at Hurley Medical Center from 01/2015 to 07/2022. NHSN surveillance definitions were used to describe the incident, recurrent cases and determine the epidemiologic categories. Hospital onset (HO) incident rate is described as per 10,000 patient days and inpatient community-onset (CO) CDI prevalence rate described as per 10,000 admissions (Figure 1).Table 1:Diagnostic stewardship and infection control interventions Results During the 7.6-year study period, overall HO CDI incident rate and inpatient CO CDI prevalence rate decreased, a percentage decrease of 34% and 53% respectively. The rates were lowest in 2020, onset of COVID-19 pandemic (percentage decrease of 22% for HO CDI incident and 7% for CO CDI prevalence rates as compared to 2019 pre-COVID-19 pandemic). There was a transient increase in 2021 (percentage increase of 36% for HO CDI incident and 14% for CO CDI prevalence rates as compared to 2019) (Figure 2, 3). HO CDI incident rates were slightly higher in men (average 11.4% difference) as compared to women except in 2017. CO CDI prevalence rates were much higher in women as compared to the men (average 13.4% difference) with the exception of 2017 and 2022.Figure 2:HO CDI Incidence rate 2015-2022, with 95% confidence intervals Conclusion HO CDI incident rate and inpatient CO CDI prevalence rates were lowest in 2020 (the onset of COVID-19 pandemic), likely secondary to computerized clinical decision support (CCDS) interventions introduced in 2019 (Table 1). The transient increase in rates seen in 2021, was likely due to increase in antibiotic utilization during the pandemic. Diagnostic stewardship played a key role in optimizing the diagnosis of CDI and improving CDI rates at our institution. There was a discrepancy of the CO CDI and HO CDI rates between the sexes, likely owing to the higher outpatient antibiotic use in women as compared to men, highlighting the importance of ambulatory stewardship.Figure 3:Inpatient CO CDI prevalence rate, with 95% confidence intervals Disclosures All Authors: No reported disclosures

The clinical features and outcomes of diabetes patients infected with COVID-19: a systematic review and meta-analysis comprising 192,693 patients

ObjectivesWe sought to explore the relevance of analyses that include critical laboratory parameters and drug treatment, clinical characteristics of diabetic patients who are infected with COVID-19, to the development of individualized treatment strategies for diabetic patients infected with COVID-19.MethodsWe searched Cochrane, Embase, FMRS, Pubmed, Springer, Web of Science databases for systematic reviews and meta-analyses to estimate the clinical characteristics and prognosis of confirmed covid-19 infections in patients with and without diabetes.ResultsOur meta-analysis included a total of 32 studies with 192,693 COVID-19 patients. Common comorbidities in the diabetic group were hypertension, cerebrovascular disease, chronic kidney disease and cardiovascular disease. We discovered that white blood cell count, neutrophil count, inflammatory marker levels, D-dimer, urea, precursor of the brain natriuretic peptide (Pro-BNP) increased and lymphocyte count, estimated glomerular filtration rate (eGFR), albumin decreased significantly in the diabetic group in laboratory test results. Compared with the non-diabetic group, the diabetic group had a higher incidence of complications in acute respiratory distress syndrome (ARDS), shock, acute heart injury, acute kidney injury and more regularly used oxygen therapy, invasive ventilation, non-invasive ventilation, continuous renal replacement therapy (CRRT), extracorporeal membrane oxygenation (ECMO) treatment. Mortality and intensive care unit (ICU) hospitalization rates were highest in the diabetic group than in the non-diabetic group (p < 0.05).ConclusionDiabetic patients hospitalized with COVID-19 have an increased risk of death, lower discharge rates, and higher ICU admission rates. Their presence of hypertension, cerebrovascular disease, chronic kidney disease (CKD), higher levels of inflammatory markers. Multiple complications are all predictors of poor outcomes in people with diabetes. Our findings will help identify elevated risk factors in diabetics, which will benefit early prediction.

P-2009. COVID-19 in Children with Hematological/Oncological Diagnoses – Exploring Reasons for Better Clinical Outcomes

Abstract Background The majority of COVID-19 infections in children, including in those with underlying hematological and oncological (Heme-Onc) diagnoses are mild with good outcome compared to adults. Postulated reasons include cross-protection from immunity against seasonal coronaviruses (HCoV’s), subdued inflammatory responses in children than in adults and differences in humoral and T-cell responses. The objectives of this study are to compare antibody responses against HCoV’s, anti-SARS-CoV-2 humoral, T-cell, and inflammatory profiles between Heme-Onc children with COVID-19 and control groups. Methods Binding IgG antibodies against Spike (S) of SARS-CoV-2, four HCoV’s (HKU1, OC43, NL63 and 229E), quantitative levels of 21 cytokines and 9 chemokines (multiplexed solid-phase electrochemiluminescence assay by Meso Scale Diagnostics/MSD) were compared among five cohorts: 1) children with Heme-Onc diagnoses and COVID-19 (n = 41) 2) healthy children with COVID-19 (n = 21) 3) adults with COVID-19 (n = 14) 4) children with multisystem inflammatory syndrome (MIS-C) [n = 23] and 5) healthy children without COVID-19 (n = 12). Additionally, T-cell responses against S and nucleocapsid (N) proteins of SARS-CoV-2 was assessed using ELISpot in Heme-Onc children a group of healthy children COVID-19. Results Anti-S antibodies and neutralizing antibodies against SARS-CoV-2 and HCoV were significantly lower in children in Heme-Onc and healthy children with COVID-19 compared to adults with COVID-19 (Figure 1). The concentration of eight pro-inflammatory cytokines and chemokines were significantly lower in Heme-Onc and healthy children compared to adults with COVID-19 and children with MIS-C. The responder T-cell frequency varied between 0 and 860/100,000 PBMC at study enrollment in children with Heme-Onc diagnoses. Conclusion In this single-center study, cross-protection from HCoV antibodies is an unlikely mechanism to explain mild COVID-19 in children, including in those with underlying hematological and oncological diagnoses. Subdued inflammatory responses to SARS-CoV-2 could be one of the factors for the mild COVID-19 disease phenotype in children. Disclosures Swetha Pinninti, MD, Moderna: Grant/Research Support|Pfizer: Grant/Research Support Suresh Boppana, MD, GSK: Advisor/Consultant|Merck: Grant/Research Support|Pfizer: Grant/Research Support

P-1947. Risk of Severe COVID-19 Reinfection among Persons Hospitalized with a Primary COVID-19 Infection, Minneapolis-St. Paul, Minnesota

Abstract Background SARS CoV-2 continues to circulate broadly making it important to understand risk factors for severe illness when reinfection occurs. We used CDC COVID-19 Hospitalization Surveillance Network (COVID-NET) data to assess reinfection, hospitalization at reinfection (hospitalized reinfection) and ICU admission at reinfection (ICU reinfection) by underlying medical conditions and ICU admission at primary infection. Methods Nonpregnant adults hospitalized 3/9/2020 - 9/30/2021 were identified through COVID-NET, surveillance that includes Minneapolis-St. Paul metropolitan area residents with a positive SARS-CoV-2 result during or ≤ 14 days before admission. Cases were matched to all reports of persons positive for SARS-CoV-2 to identify reinfections, defined as a positive SARS-CoV-2 test > 90 days after the initial positive result through 4/17/2024. Logistic regression was used to assess reinfection and severity of reinfection adjusted for age, sex, race/ethnicity, and vaccination status (aOR). Results 6,434 hospitalized persons met the COVID-NET case definition for their primary infection; 1,189 (18%) had a reinfection. 356 (30%) of the reinfection cases were hospitalized and 51 (14%) of those hospitalized had ICU admission. Having any underlying condition was associated with reinfection (aOR 1.62, 95% CI 1.18, 2.23) and hospitalized reinfection (aOR 2.16, 95% CI 1.27, 3.69). Cardiovascular disease was associated with reinfection (aOR 1.72, 95% CI 1.28, 2.31). Cardiovascular disease (aOR 3.03, 95% CI 1.87, 4.90), blood disorders (aOR 2.42, 95% CI 1.03, 5.37), and renal disease (aOR 1.85, 95% CI 1.12, 3.06) were associated with hospitalized reinfection. All 51 ICU reinfections and 14 reinfection deaths had an underlying condition. Primary ICU admission was not associated with reinfection or hospitalized reinfection but was associated with ICU reinfection (aOR 5.26, 95% CI 1.65, 16.73). Conclusion Among patients hospitalized with COVID-19, underlying conditions and primary ICU admission were associated with severe outcomes during reinfection. These results highlight the continued importance of prevention strategies like vaccination and treatment to mitigate severe illness among patients at highest risk. Disclosures All Authors: No reported disclosures

P-1973. Characteristics, Clinical Management, and Outcomes of Immunocompromised Patients Diagnosed with COVID-19 in the Outpatient Setting in France

Abstract Background Most COVID-19 patients are treated in primary healthcare settings in France, where patients are typically assigned one general practitioner (GP) for the continuum of their care. The risk of progression to severe disease and death is higher in immunocompromised patients with COVID-19. We descriptively summarize the characteristics, documented clinical management and outcomes of immunocompromised patients diagnosed with COVID-19 in the outpatient setting in France.Table 1:Characteristics of immunocompromised patients diagnosed with COVID-19 in the outpatient setting, 2022-2023 Methods Adults with an immunocompromised condition and a documented diagnosis of COVID-19 in 2022-2023 were identified from The Health Improvement Network (THIN). THIN collects anonymized patient-level data from electronic health records of GPs and some specialists in the outpatient setting representative of the French population. Index was the first documented COVID-19 diagnosis, and patients with COVID-19 diagnosis the 3-months prior to index were excluded. COVID-19 treatments prescribed within1-month post-index were examined. Reinfection was defined as COVID-19 infection documented in outpatient setting at least 3 months after index.Table 2:Clinical management of immunocompromised patients diagnosed with COVID-19 in the outpatient setting, 2022-2023 Results Overall, 13,354 immunocompromised patients with COVID-19 with a median age of 59 years (IQR:47—72), and 66% female were identified. Majority had an immunocompromised condition of active cancer diagnosed in the 3-years prior to index (76%). 64% had at least another key comorbidity documented in the 12-months prior (Table 1). Treatments prescribed included antibacterials (30%), corticosteroids (17%), nirmatrelvir/ritonavir (5%); COVID-19 was documented as the reason for antibacterial prescriptions (15% overall) and corticosteroids (8% overall) (Table 2). Post-index, 14% had at least one additional outpatient visit within 7 days, 37% within 30 days, and 54% within 60 days with an average 0.9 (SD=1.1) visits within 60 days (Table 3).Table 3:Clinical outcomes of immunocompromised patients diagnosed with COVID-19 in the outpatient setting, 2022-2023 Conclusion The use of nirmatrelvir/ritonavir was low among immunocompromised patients with COVID-19 diagnosed in outpatient visits. In contrast, inappropriate prescription of corticosteroids and antibacterials was frequent. There is a need for effective treatment options for immunocompromised patients as they face a significant healthcare burden with frequent follow-up visits and COVID-19 reinfections. Disclosures Essy Mozaffari, PharmD, MPH, MBA, Gilead Sciences, Inc.: Employee|Gilead Sciences, Inc.: Stocks/Bonds (Public Company) Aastha Chandak, PhD, Gilead Sciences Inc.: My organization (Certara) was contracted by Gilead to conduct this study Mark Berry, PhD, Gilead Sciences, Inc.: Employee|Gilead Sciences, Inc.: Stocks/Bonds (Public Company) Gaelle gusto, PhD, Gilead Sciences Inc.: My organization (Certara) was contracted by Gilead to conduct this study Giancarlo Pesce, Sr Consultant, Gilead Sciences Inc.: My organization (Certara) was contracted by Gilead to conduct this study Agnese Restuccia, PhD, Gilead Sciences: Stocks/Bonds (Private Company) Michele Bartoletti, MD, PhD, Advan pharma: Advisor/Consultant|Advan pharma: Honoraria|Biomereux: Honoraria|Gilead: Advisor/Consultant|Gilead: Honoraria|Infectopharma: Advisor/Consultant|Msd: Advisor/Consultant|Msd: Grant/Research Support|Msd: Honoraria|Pfizer: Honoraria Paul LOUBET, MD, PhD, Astrazeneca: Advisor/Consultant|Gilead: Advisor/Consultant|Moderna: Advisor/Consultant|Pfizer: Advisor/Consultant

P-1918. Incidence of viral rebound in hospitalized COVID-19 patients

Abstract Background Viral rebound, characterized by a resurgence of viral activity after initial suppression, presents a potential threat to infection control within healthcare settings. We aimed to investigate the incidence of viral rebound in patients hospitalized for COVID-19. Methods The retrospective study included symptomatic adults admitted for COVID-19 to a tertiary hospital in Taiwan during 1 January 2022 to 31 December 2022. Viral rebound was defined as an increase of △Ct ≥ 5 units or a new positive test after having tested negative during 10-30 days after COVID-19 diagnosis. The indication of antiviral agent was evaluated by physician according to initial severity and risks to develop severe COVID-19. The patients with prior COVID-19 infections, receipt of ≥ 2 antiviral agents, incomplete treatment course of antiviral agent, or active problem for hospitalization other than COVID-19 were excluded. Results Of the included 354 participants, 26 received Paxlovid, 98 received molnupiravir, 54 received 3-day remdesivir, 101 received 5-day remdesivir, and 84 didn’t receive any antiviral agent. The incidence of viral rebound was higher in patients not receiving antiviral agent (n=75) compared to those who received either antiviral therapy (n=279) (17.3% vs. 11.5%, p=0.18). Additionally, the duration from COVID-19 diagnosis to onset of viral rebound was similar between the two groups (16.2 days vs. 14.3 days, p=0.20). Among the 148 with severe COVID-19, viral rebound was higher in patients without antiviral agent exposure (n=47) compared to those who received 5-day remdesivir (n=101) (21.3% vs. 15.8%, p=0.18). In 206 with non-severe disease, no significant differences were found in the incidence of viral rebound between patients who received Paxlovid (n=26) and molnupiravir (n=98) (11.5% vs. 7.1%, p=0.44). Conclusion Our study highlights the risk of viral rebound in hospitalized COVID-19 patients. Patients without antiviral treatment had a higher rebound incidence. Among severe cases, antiviral therapy reduced rebound rates, underscoring its importance. Interestingly, antiviral choice did not significantly affect rebound incidences in non-severe cases. These findings stress the crucial role of antiviral therapy in infection control strategies. Disclosures All Authors: No reported disclosures

Long COVID and its risk factors in migrants: a nationwide register study from Sweden

BackgroundMany studies have found more severe COVID-19 outcomes in migrants and ethnic minorities throughout the COVID-19 pandemic, while recent evidence also suggests higher risk of longer-term consequences. We studied the risk of a long COVID diagnosis among adult residents in Sweden, dependent on country of birth and accounting for known risk factors for long COVID.MethodsWe used linked Swedish administrative registers between March 1, 2020 and April 1, 2023, to estimate the risk of a long COVID diagnosis in the adult population that had a confirmed COVID-19 infection. Poisson regressions were used to calculate incidence rate ratios (IRR) of long COVID by country/region of birth. The contribution of sex, preexisting health status, disease severity, vaccination status, and socioeconomic factors to differences in long COVID diagnosis by country/region of birth were further investigated.ResultsOf the 1,869,188 persons diagnosed with COVID-19 that were included, 7539 had received a long COVID diagnosis. Compared with residents born in Sweden, we found higher risks of long COVID among migrants from East Europe (IRR: 1.44 CI: 1.29–1.60), Finland (IRR: 1.36 CI: 1.15–1.61), South Asia (IRR: 1.28 CI: 1.03–1.59), Other Asia (IRR: 1.35 CI: 1.13–1.62), Other Africa (IRR: 1.48 CI: 1.17–1.87), and the Middle East (IRR: 1.43 CI: 1.27–1.63) in models adjusted for age and sex. We discovered that disease severity, i.e., whether the person was hospitalized (IRR: 18.6 CI: 17.3–20.0) or treated in an intensive care unit (IRR: 120.5 CI: 111.7–129.8), primarily contributed to the higher risk of long COVID found in migrants while the contribution of vaccinations and social conditions were moderate. Preexisting health problems did not contribute to the increased risk of long COVID in migrants.ConclusionsThe greater exposure and impact of the COVID-19 virus among migrants also affected longer-term consequences. Disease severity was the most important risk factor for long COVID in migrants. The findings emphasize the need for targeted health interventions for migrant communities during an infectious disease pandemic, such as strategic vaccination campaigns and extending social insurance schemes, focusing on reducing disease severity to mitigate the longer-term health consequences of an infection.

P-1963. Changes in COVID-19 Sentiment and Behavior among Healthcare Professionals Over Time in a Rural State

Abstract Background We assessed attitudes towards COVID-19 and use of COVID-19 infection prevention practices during the pandemic among employees at an academic health center in a rural state.Figure 1:Reported Level of Worry about Spreading SARS- CoV-2 Methods We invited all employees aged >18 years reporting prior COVID-19 on a screening survey to participate and randomly selected other participants (Ps) from among those not reporting prior COVID-19 to create a study cohort of 302 participants. Ps completed surveys at 3-month intervals (T0, T3, T6, T9). We used the Chi-squared test to assess changes in Ps’ responses between individual time points.Figure 2:Reported Willingness to Go into Public Places Results At T0 most Ps thought their risk of acquiring COVID-19 either in the hospital or the community was low (< 3%) and < 20% worried that they or their household members would “catch COVID-19.” However, 45% of Ps were worried about spreading SARS-CoV-2 asymptomatically. Ps’ perceived likelihood of getting COVID-19 at the hospital and in the community did not change. The percent of Ps who were very worried about getting COVID-19 was significantly lower at T1 (1.7%), T2 (2.6%), and T3 (5.7%) than at T0 (11.3%; P < .05 for all). The percent of Ps who were very worried that household members would get COVID-19 decreased from T0 (16.6%) to T1 (8.0%; P = .03). After vaccines were introduced, Ps tended to report being less worried about spreading COVID-19, more willing to go to public places and less likely to wear face masks in the public. Shortly after the Delta variant emerged, these sentiments changed direction but did not return to their baseline cautiousness level. Shortly before the Omicron variant emerged, the sentiments of those who were seropositive at any time and those who remained seronegative during the study period diverged, with the latter being more worried about asymptomatic spread, less willing to go to public places and more willing to mask in the community than those who seroconverted. Consistent with these changes, 21 of 26 (80.8%) seroconversions occurred during the Omicron surge.Figure 3:Changes in Reported Use of Face Coverings in Public Conclusion Some attitudes and behaviors changed over time possibly related to vaccine availability and the predominant SARS-Co-V2 variant. Ps who remained seronegative tended to be more concerned about getting COVID-19 and were more likely to continue using COVID-19 infection prevention practices. Disclosures Daniel Diekema, MD, MS, D(ABMM), Affinity Biosensors: Grant/Research Support|bioMerieux, Inc: Grant/Research Support Loreen Herwaldt, MD, 3M: Grant/Research Support|PDI: Grant/Research Support

P-1033. Post-transplant Outcomes in Kidney Transplant Recipients with Invasive Fungal Infections Prior vs. After the Emergence of SARS-CoV2

Abstract Background Invasive fungal infections (IFIs) are a serious complication in kidney transplant recipients (KTRs), leading to increased mortality and graft failure. Given changes in care associated with pandemic conditions and potential compounding effects of COVID-19 infection, we sought to determine whether the emergence of SARS-CoV2 contributed to a rise in adverse transplant outcomes associated with IFIs. Methods We performed a retrospective study of adult KTRs transplanted at Johns Hopkins from 2012-2018 with follow up through 5/2023. IFI diagnoses were based on EORTC/MSGERC criteria. If a patient had more than one IFI, the date of first IFI served as the index exposure. KTRs with and without IFIs were matched 1:1 on time-post-KT. We followed patients until all-cause graft loss (ACGL), a composite outcome of graft failure and mortality, and estimated cumulative incidence of ACGL prior vs. after emergence of SARS-CoV2 in 2/2020. We then determined whether the association between IFI and ACGL varied before vs during SARS-CoV2 pandemic using Cox regression with an interaction term and adjusting for age, transplant risk, and cardiovascular disease.Table 2.First post-transplant invasive fungal infection among kidney transplant recipients prior vs. post emergence of SARS-CoV2 Results Among 1453 KTRs, 79 (5.4%) had proven/probable IFIs of which 12 occurred after emergence of SARS-CoV2 (Table 1). Yeast caused the majority of IFIs (50/79) over the study period, but mold (5/12) and yeast (6/12) were equally represented among IFIs occurring after the emergence of SARS-CoV2 (Table 2). Prior to the pandemic, ACGL occurred in 66% (44/67) of KTRs with IFIs compared to 31% (414/1338) of KTRs without IFIs (log-rank p < 0.001). During the pandemic, ACGL occurred in 75% (9/12) of KTRs with IFIs compared to 31% of KTRs without IFIs (log-rank p < 0.001) (Fig 1). KTRs with IFIs had a 2-fold greater risk of ACGL (aHR 2.05, 95% CI 1.17-3.57, p = 0.012) prior to the pandemic and a 5.5-fold greater risk of ACGL (aHR 5.54, 95% CI 1.17-26.24, p < 0.01) during the pandemic. The risk of ACGL associated with IFIs was significantly different after the emergence of SARS-CoV2 (p-interaction term < 0.001; Fig 2).Figure 1.ACGL-free survival of KTR with IFIs vs. without IFIs Conclusion KTRs with IFIs had higher rates of ACGL during the pandemic, and molds constituted a greater proportion of the IFIs during the pandemic. The emergence of SARS-CoV2 seems to have shifted the epidemiology of IFIs among KTRs, leading to increased ACGL.Figure 2.ACGL-free survival of KTR with IFIs prior vs. after emergence of SARS-CoV2 Disclosures Nitipong Permpalung, MD, MPH, CareDx: Grant/Research Support|Cidara Therapeutics: Grant/Research Support|ClearView: Advisor/Consultant|IMMY Diagnostics: Grant/Research Support|Merck: Grant/Research Support|Pearl Diagnostics: Grant/Research Support|Pulmicide: Advisor/Consultant|Scynexis: Grant/Research Support

P-355. Skin Lesions and the Use of Personal Protective Equipment in Healthcare Workers from Lima, Peru during the COVID 19 Pandemic

Abstract Background During the COVID-19 pandemic, healthcare workers relied on personal protective equipment (PPE) to mitigate COVID-19 infections. However, prolonged use of PPE led to a risk of developing skin lesions (SL). In our study, we evaluated the frequency, characteristics and factors associated with SL while using PPE. Methods We conducted a cross-sectional study to survey 219 healthcare workers in two hospitals in Lima, Peru between September 2020 and May 2021. The survey focused on reporting SL related to PPE use during their time as healthcare workers amidst the pandemic. Eligible participants were required to be hospital personnel that was actively working on-site and utilizing PPE. Results Most commonly used PPE items included N95 respirator (96.80%), disposable gown (80.37%), head cover (77.63%), eye gear (60.73%) and surgical masks (59.28%). 176 participants (80.37%) reported skin lesions while using PPE. The most prevalent SL were erythema (63, 36.42%), comedones (26, 15.03%) and erosions (25, 14.45%). Common locations for SL were the nasal bridge (93, 51.96%) and cheeks (43, 24.02%). Additionally, 91 (51.70%) participants reported seeking treatment, with self-medication (47, 51.65%) being the prevalent method. Among the participants, 80 (37.21%) reported using prevention methods being the most common, adhesive tape or bandages (46, 57.50%). SL were associated with being a medical intern (PR 2.46, p=0.014), medical attending (PR 2.35, p=0.019), medical resident (PR 2.69, p=0.006) and nurse (PR 2.44, p=0.014). Eye gear, shoe covers and overalls were found to be risk factors for SL (PR 1.16, p=0.048; PR 1.21, p=0.007; PR 1.15, p=0.031). Participants who had a history of previous skin conditions were 1.19 (p=0.008) times more likely to have SL. In the adjusted model, working in the ICU (PR 1.31, 95%CI 1.02-1.68, p=0.034), working more than 12 hours per day (PR 1.49, 95%CI 1.07-2.08, p=0.017), presenting a skin burning sensation and skin dryness (PR 1.21, 95%CI 1.03-1.42; p=0.021; PR 1.41, 95%CI 1.04-1.92, p=0.026) were associated risk factors. Conclusion By documenting the prevalence of skin lesions in healthcare worker due to PPE usage we underscore the need for biosafety monitoring, as the presence of lesions can lead to PPE misusage, increasing the risk of respiratory infections. Disclosures All Authors: No reported disclosures

P-2032. The Time to Return to Work in Healthcare Workers With COVID-19 Infection Treated With Ensitrelvir, a Novel Oral Inhibitor of 3C-Like Protease of SARS-COV-2

Abstract Background Early diagnosis and treatment with antivirals are important in COVID-19 management. This study aimed to investigate the time to return to work and COVID-19 symptom improvement in healthcare workers treated with ensitrelvir. Methods A retrospective single-center, observational study was conducted to assess the effect of ensitrelvir on the time to return to work and the resolution of symptoms at the time of return in healthcare workers diagnosed with COVID-19 between June and September 2023 during the Omicron dominant period. The differences in patient background between the ensitrelvir treated group and no antiviral treatment group was not adjusted, and we conducted descriptive analysis. The criteria for returning to work were defined as improvement of symptoms and an antigen quantification test result of ≤ 100 pg/mL after the 6th day of onset. Results A total of 102 healthcare workers were registered, and ensitrelvir was administered in 60 cases. The average number of days from onset of symptoms to ensitrelvir administration was 0.8 days. The female proportion was 76.7% and 78.6% in the ensitrelvir-treated and non-treated groups, respectively, with average ages of 38.2 and 30.6 years in each group, respectively. The severity of COVID-19 was mild in all cases. No side effects were observed in the ensitrelvir-treated group. The average time to meet the criteria for returning to work was 6.9 days in the ensitrelvir treated group and 7.7 days in the non-treated group. 35 patients (58.3%) in the ensitrelvir-treated group and 15 patients (35.7%) in the non-treated group experienced recovery (fever resolution and disappearance of COVID-19 symptoms) on the day of returning to work. Additionally, 25 patients (41.7%) in the ensitrelvir-treated group and 27 patients (64.3%) in the non-treated group experienced improvement (fever resolved but some symptoms remained) on the day of returning to work. Conclusion This study showed that early treatment of COVID-19 with ensitrelvir may improve symptoms and reduce the number of days to return to work. The results suggest that early antiviral drug administration to healthcare workers may contribute to the maintenance and continuity of routine healthcare, thereby avoiding Healthcare workers shortage. Disclosures Makoto Katsuta, Shionogi & Co., Ltd.: Lecture fees Takuhiro Sonoyama, MD, Shionogi & Co., Ltd.: Stocks/Bonds (Private Company) Tomoyoshi Yamaguchi, MD, Shionogi & Co., Ltd.: Lecture fees

P-1331. Effect of Transfusion-Transmitted Infection Pre-Donation Deferrals on Subsequent Donations in a Military Blood Donation Center

Abstract Background To minimize the risk of transfusion-transmitted infections (TTI), all prospective blood donors are required to undergo extensive screening via questionnaire and physical exam. Donors who report behaviors or conditions that may increase risk of TTIs are temporarily deferred from donating. In recent years, significant changes to the deferral policy have been instituted to expand the donor eligibility pool and mitigate the blood supply crisis. In this study, we evaluate the impact of deferring donors at increased risk of TTI on future donation attempts to further inform how these policies may affect the military population. Methods This retrospective chart review evaluated all blood donors with pre-donation deferrals at a single site between October 2019 to December 2022. Among the fourteen deferral categories, seven were classified as behaviors or conditions that increase risk of TTI including: taking an anti-infective, travel to malaria-endemic area, recent tattoo or piercing, recent sexually transmitted infection (STI), recent COVID-19 infection, man who has sex with men (MSM), or other infectious concern. The rate of donation reattempts within the study period was assessed in donors deferred for TTI risk and compared to that of donors deferred for low hemoglobin matched by sex, age, and BMT status. Results 6,352 (12.8%) of the 49,613 blood donors identified during the study had a pre-donation deferral. Over half of all deferrals were due to anemia (54.2%) and approximately a tenth for TTI risk (Table 1). We found that donors who were deferred for TTI risk were significantly less likely to attempt redonation during the study period compared to those deferred for anemia (p< 0.001). On multivariate analysis, donors deferred for MSM and travel or residence in a malaria-endemic area were independently associated with a decreased redonation attempt rate and increased time to reattempt (Table 2, Figure 1). Time to redonation for deferred blood donors with a TTI risk (dark green) or anemia (light blue). Conclusion Pre-donation deferrals for TTI risk were associated with a decreased rate of redonation and increased time to reattempt compared to donors deferred for anemia. Disclosures All Authors: No reported disclosures

P-2064. COVID-19 Vaccination-infection Status and Immunological Profile: Identification of High-Risk Population for Targeted Booster Immunization In India

Abstract Background The immunological profiles and predictors of immune response in people with hybrid immunity, resulting from a combination of natural infection and vaccination, particularly in regions where non-mRNA vaccines were administered, remain less understood. Methods This was a cross-sectional study done at AIG Hospitals, Hyderabad, India. Consecutive participants were enrolled, and sampled for immunological testing. The study population was divided into six cohorts based on their infection and vaccination status. Immunological assays were performed to measure anti-spike protein and interferon-γ release assay. Hospitalization rates were compared in all groups. Chi-square test was used to compare categorical variables, and the Mann-Whitney U test was used for comparing medians. Post-hoc Dunn test was used for pairwise comparison. Bonferroni adjustment for p-value was performed for multiple pairwise comparisons. Linear regression model was used appropriately to find predictors of antibody titres. Results A total of 1040 patients were enrolled in the study. The population was divided into six cohorts: Unvaccinated, Primary, Booster, Hybrid (Pre-Omicron only), Hybrid (Omicron only), and Hybrid (Both). Antibody titres and IGRA levels were found to be statistically higher in the Hybrid (both infection) group (Table 1 and Figures 1a & 1b). The linear regression model showed factors predicting antibody response (Table 2). Age and hypertension were independent (negative) predictors of antibody levels. During the follow-up (median 30.7 [26.6 – 34.4 months]) of 1008 patients, 770 (76.4%) had a documented COVID infection with Omicron. Hospitalization was evaluated in three groups: Hybrid, vaccination only and unvaccinated. The incidence was significantly lower in the Hybrid group; log-rank test: p < 0.001. (Figure 2) Conclusion The prevalence of hybrid immunity was high in the study population. Individuals above 60 years old and with comorbidities are more likely to have lower antibody titers. Immunized patients were protected against hospitalization. There is a need for prioritized immune-boosting efforts in high-risk individuals. Disclosures All Authors: No reported disclosures

P-1908. The Relationship Between Long COVID and PHQ-4 Measures of Emotional Health

Abstract Background The COVID-19 pandemic was one of the most devastating public health crises in US history. Millions of Americans experience ongoing symptoms, often termed “Long COVID.” Long COVID (LC) has been defined as symptoms lasting 3 months or longer that were not present prior to the COVID infection. LC’s neurological effects have been associated with psychological issues like depression. Furthermore, given that many individuals with LC report difficulty getting treatment for these symptoms, the emotional effects associated with LC may be profound. Methods The US Census Bureau conducts an ongoing study called the Household Pulse Survey, with the purpose of measuring emergent social and economic matters facing U.S. households. Data analyzed was collected January 9 - February 5, 2024. Respondents were asked about their self-reported COVID-19 experiences and their mental health, as measured by the Patient Health Questionnaire-4 (PHQ-4) for depression and anxiety. The survey was conducted in English and Spanish and the survey sample was N=68,544. Data were analyzed using χ2 and between group contrast analysis. Results Of those surveyed, N=9,298 or 16.5% reported experiencing LC. When asked about their experiences during the last two weeks, 60.1% reported feeling anxious on several days or more, vs. 40.5% of those who had experienced COVID-19 but had no long term symptoms (termed Short COVID or SC) and 38.7% of those who had not contracted COVID-19 (called No COVID or NC), with LC significantly higher than both other groups (p< .05). Fully 51.1% of LC respondents were unable to stop or control their worrying, vs. 29.1% SC and 31.9% NC= (both comparisons vs. LC, p< .05). Similarly, those with LC were also significantly more likely to report having experienced little pleasure or interest in doing things (47.5% vs. 25.2% SC and 30.4% NC, p< .05) and feeling down, depressed or hopeless in the past two weeks (48.3% vs. 27.4% SC and 30.9% NC, p< .05). Conclusion Many Americans surveyed report experiencing LC and this appears to be associated with significant negative mental health effects, as measured by the PHQ-4. Further research should examine the relationship between LC and mental health, as well as mechanisms of how these factors relate to one another. Disclosures All Authors: No reported disclosures