Assess Vaccine Effectiveness Research Articles

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)

The effect of SARS-CoV-2 infection and COVID-19 vaccination during pregnancy on neonatal outcomes.

This study explored the effect of SARS-CoV-2 infection and COVID-19 vaccination during pregnancy on neonatal outcomes among women from the general Dutch population. VASCO is an ongoing prospective cohort study aimed at assessing vaccine effectiveness of COVID-19 vaccination. Pregnancy status was reported at baseline and through regular follow-up questionnaires. As an extension to the main study, all female participants who reported to have been pregnant between enrolment (May-December 2021) and January 2023 were requested to complete an additional questionnaire on neonatal outcomes. Multivariable linear and logistic regression analyses were used to determine the associations between self-reported SARS-CoV-2 infection or COVID-19 vaccination during pregnancy and neonatal outcomes, adjusted for age, educational level, and presence of a medical risk condition. Infection analyses were additionally adjusted for COVID-19 vaccination before and during pregnancy, and vaccination analyses for SARS-CoV-2 infection before and during pregnancy. Of 312 eligible participants, 232 (74%) completed the questionnaire. In total, 196 COVID-19 vaccinations and 115 SARS-CoV-2 infections during pregnancy were reported. Infections were mostly first infections (86; 75%), caused by the Omicron variant (95; 83%), in women who had received ≥1 vaccination prior to infection (101; 88%). SARS-CoV-2 infection during pregnancy was not significantly associated with gestational age (β = 1.7; 95%CI: -1.6-5.0), birth weight (β = 82; -59 to 223), Apgar score <9 (odds ratio (OR): 1.3; 0.6-2.9), postpartum hospital stay (OR: 1.0; 0.6-1.8), or neonatal intensive care unit admission (OR: 0.8; 0.2-3.2). COVID-19 vaccination during pregnancy was not significantly associated with gestational age (β = -0.4; -4.0 to 3.2), birth weight (β = 88; -64 to 240), Apgar score <9 (OR: 0.9; 0.4-2.3), postpartum hospital stay (OR: 0.9; 0.5-1.7), or neonatal intensive care unit admission (OR: 1.6; 0.4-8.6). In conclusion, this study did not find an effect of SARS-CoV-2 infection or COVID-19 vaccination during pregnancy on any of the studied neonatal outcomes among a general Dutch, largely vaccinated, population. Together with data from other studies, this supports the safety of COVID-19 vaccination during pregnancy.

Bias and negative values of COVID-19 vaccine effectiveness estimates from a test-negative design without controlling for prior SARS-CoV-2 infection

Test-negative designs (TNDs) are used to assess vaccine effectiveness (VE). Protection from infection-induced immunity may confound the association between case and vaccination status, but collecting reliable infection history can be challenging. If vaccinated individuals have less infection-induced protection than unvaccinated individuals, failure to account for infection history could underestimate VE, though the bias is not well understood. We simulated individual-level SARS-CoV-2 infection and COVID-19 vaccination histories and a TND. VE against symptomatic infection and VE against severe disease estimates unadjusted for infection history underestimated VE compared to estimates adjusted for infection history, and unadjusted estimates were more likely to be below 0%, which could lead to an incorrect interpretation that COVID-19 vaccines are harmful. TNDs assessing VE immediately following vaccine rollout introduced the largest bias and potential for negative VE against symptomatic infection. Despite the potential for bias, VE estimates from TNDs without prior infection information are useful because underestimation is rarely more than 8 percentage points.

Case-controlled study to compare the neutralizing antibody amongst fully vaccinated breakthrough infections in third wave of COVID-19 and asymptomatic healthcare workers

BackgroundThe SARS-CoV-2 (COVID-19) pandemic declared in March 2020 continues to impact millions globally. India initiated a large-scale COVID-19 vaccination campaign in January 2021 using the CovishieldTM vaccine. Monitoring neutralizing antibody (NAb) levels is essential for assessing vaccine effectiveness, but data on NAb levels after completing two doses of CovishieldTM are limited. This study aimed to investigate the NAb profile among fully vaccinated individuals. MethodsConducted during the third wave of the pandemic starting in January 2022, this study included individuals who received the first two doses of CovishieldTM and visited the flu clinic or vaccination center. NAb levels were measured using an approved kit and "Blocking ELISA" method. Symptomatic individuals underwent COVID-19 real-time polymerase chain reaction (RT-PCR) testing. ResultsThe study included 299 individuals with a median age of 26 years (IQR-11 years; male preponderance: 81.9%). NAb was detected in 91.5% (n=274) of the participants. The mean neutralizing percentage inhibition was 77.26%±26.26%. Significant relationships were found between neutralizing percentage inhibition and past COVID-19 infection (p=0.0005), blood groups (B+ve had the highest Ab inhibition, p=0.0003), and age (p=0.01). No significant correlation was observed with gender (p=0.11), time since the second vaccine dose (p=0.32), and time from the last COVID19 infection (p=0.48). ConclusionDuring the early stages of the third wave of COVID-19 in India (January 2022), a high seroprevalence of NAb was observed among fully vaccinated individuals. Breakthrough infections occurred but with reduced severity. Breakthrough cases had higher percentage inhibition, high NAb positivity, longer time since the last COVID-19 infection, and older age.

Effectiveness of bivalent HPV vaccination against genital HPV DNA-positivity of a catch-up campaign at age 13–16 years compared to routine vaccination at age 12 years: a biennial repeated cross-sectional study

BackgroundThe Netherlands is one of few countries worldwide which has used the bivalent HPV vaccine for girls-only for over a decade. This allows assessment of vaccine effectiveness (VE) against female genital HPV DNA-positivity of this vaccine in an observational post-licencing real-world setting. Additionally, it is unclear whether catch-up vaccination campaigns result in similar VE as routine vaccination. Therefore, type-specific and grouped VE were assessed and compared for women who had been eligible for catch-up vaccination at 13–16 years with those who had been eligible for routine vaccination at 12 years.MethodsPASSYON is a Dutch biennial repeated cross-sectional (2011–2021) study among sexual health clinic clients aged 16–24 years old. Women provided self-collected vaginal samples, questionnaires on demographics and sexual behaviour were administered, and women self-reported HPV vaccination status. Samples were analysed using a PCR-based assay (SPF10-LiPA25). Type-specific and grouped VE estimates, adjusted with propensity score stratification, were assessed against genital positivity for 14 HPV types. VE for targeted and non-targeted genotypes were compared between women who had been eligible for the catch-up and those who had been eligible for routine vaccination.ResultsThe study included 4488 female participants who had been eligible for HPV vaccination and provided genital swabs (1561 eligible for catch-up, 2927 for routine vaccination). Very high VE against genital HPV-16 and HPV-18 was observed (resp. 93.5% and 89.5%) and significant cross-protection against six other genotypes (HPV-31/33/35/45/52/58), varying from 18.0% (HPV-52) to 79.6% (HPV-45). VE estimates were comparable between women who had been eligible for the catch-up campaign and those eligible for routine vaccination: VE HPV-16/HPV-18: 92.2% (95%CI: 87.9–94.9) vs. 91.8% (95%CI: 86.0–95.2).ConclusionsIn real-world settings, the VE of bivalent vaccine is high against targeted genotypes, with cross-protection against 6 other genotypes. Catch-up campaigns up to age 16 years can be as effective as routine vaccination at age 12, although it is recommendable to provide HPV vaccination at an age at which most are likely not sexually active yet. This may inform countries considering catch-up campaigns when introducing or extending the use of HPV vaccination within their national immunisation programmes.

Validation Assessment of Privacy-Preserving Synthetic Electronic Health Record Data: Comparison of Original Versus Synthetic Data on Real-World COVID-19 Vaccine Effectiveness.

To assess the validity of privacy-preserving synthetic data by comparing results from synthetic versus original EHR data analysis. A published retrospective cohort study on real-world effectiveness of COVID-19 vaccines by Maccabi Healthcare Services in Israel was replicated using synthetic data generated from the same source, and the results were compared between synthetic versus original datasets. The endpoints included COVID-19 infection, symptomatic COVID-19 infection and hospitalization due to infection and were also assessed in several demographic and clinical subgroups. In comparing synthetic versus original data estimates, several metrices were utilized: standardized mean differences (SMD), decision agreement, estimate agreement, confidence interval overlap, and Wald test. Synthetic data were generated five times to assess the stability of results. The distribution of demographic and clinical characteristics demonstrated very small difference (< 0.01 SMD). In the comparison of vaccine effectiveness assessed in relative risk reduction between synthetic versus original data, there was a 100% decision agreement, 100% estimate agreement, and a high level of confidence interval overlap (88.7%-99.7%) in all five replicates across all subgroups. Similar findings were achieved in the assessment of vaccine effectiveness against symptomatic COVID-19 Infection. In the comparison of hazard ratios for COVID 19-related hospitalization and odds ratio for symptomatic COVID-19 Infection, the Wald tests suggested no significant difference between respective effect estimates in all five replicates for all patient subgroups but there were disagreements in estimate and decision metrices in some subgroups and replicates. Overall, comparison of synthetic versus original real-world data demonstrated good validity and reliability. Transparency on the process to generate high fidelity synthetic data and assurances of patient privacy are warranted.

Molecular epidemiology and vaccine compatibility analysis of seasonal influenza A viruses in the context of COVID-19 epidemic in Wuhan, China.

The COVID-19 pandemic had a significant impact on the global influenza vaccination and the epidemics of seasonal influenza. To further explore the molecular epidemiology of influenza viruses and assess vaccine effectiveness, we collected influenza cases in Wuhan during the 2022-2023 influenza season. Among 1312 clinical samples, 312 samples tested positive for influenza viruses using reverse transcription polymerase chain reaction. These positive samples included 146A/H1N1 subtypes (46.8%), 164A/H3N2 subtypes (52.6%) and 2 influenza B virus types (0.6%). Based on the whole genome sequence information of hemagglutinin (HA) and neuraminidase (NA) from 27A/H1N1 influenza virus strains and 26A/H3N2 influenza virus strains obtained in this study, a phylogenetic analysis was conducted. The analysis revealed that all A/H1N1 strains belonged to the evolutionary branch 6B.1A.5a.2a, and they exhibited specific substitutions at positions K71Q, Q206E, E241A, and R276K. Similarly, all A/H3N2 strains were classified into the 3C.2a1b.2a.1a subclade and displayed amino acid substitutions at positions S172H, N175Y, I176T, K187N, and S214P. Notably, the A/H3N2 strains also acquired a new potential glycosylation site at position N174. Using an epitope model, the predicted vaccine effectiveness was assessed for the A/H1N1 and A/H3N2 strains. The predicted vaccine effectiveness against the Wuhan influenza epidemic strain was over 85% for the A/H1N1 vaccine strain. However, the effectiveness against the A/H3N2 vaccine strain was only 48.7%. To further verify the protection of influenza vaccine against circulating influenza viruses in the region, we conducted in vivo and in vitro animal studies. The results of in vitro neutralization experiment showed that rabbit serum antibodies inoculated with quadrivalent isolated influenza vaccine had neutralization ability against all 24 isolated influenza viruses. In vivo experiments showed that vaccinated mice had fewer lung lesions when infected with the influenza strain circulating in Wuhan, suggesting that vaccination can effectively reduce the occurrence of severe lung damage. These findings emphasize the importance of accurately predicting seasonal influenza strains for effective influenza prevention and control, especially during the co-circulation of SARS-CoV-2 and influenza viruses. This study provides valuable information on the seasonal influenza virus in Wuhan during the COVID-19 pandemic and serves as a basis for vaccine prediction and updates.

Molecular characterization of Mumps virus genotype C detected from Dibrugarh district of Assam, India.

Background & objectives Mumps, a contagious disease caused by the mumps virus (MuV) involves parotid gland inflammation, with potential complications affecting organs other than the parotid glands and central nervous system. Despite successful vaccination, a resurgence of mumps occurred, raising concerns about vaccine effectiveness. This study aimed to examine the entire genome of a representative MuV genotype C from Dibrugarh, Assam, and compare it with references to detect genetic variations in the circulating strain. Methods Representative MuV genotype C from our published study was subjected to whole genome sequencing. MuV genome was analyzed against the reference genome and vaccine strains before being subjected to mutational profiling, N-glycosylation site determination, and phylogenetic analysis. The Immune Epitope Database was used for epitope screening, and selected epitopes were mapped against Assam MuV for conservancy studies. Results Mutational analysis of Assam MuV with WHO (World health Organization) reference, vaccine strains Jeryl Lynn (Genotype A), and L Zagreb (Genotype N) showed variations in seven genes. Phylogenetic analysis established Assam MuV as genotype C. Epitope conservancy analysis highlighted subtle variations in experimentally determined T-cell epitopes for HN and F proteins, emphasizing overall epitope stability. Interpretation & conclusions Genome sequencing has evolved into a standard and potent method for investigating and recording circulating MuV as it provides information on surveillance, mutation analysis, and transmission dynamics. Despite mumps' global effect, genomic studies are limited, particularly in north-east. Our study provides first comprehensive whole-genome report on circulating MuV genotype C in Assam. This research contributes vital genomic data, filling gaps in MuV genetic epidemiology, supporting global research, and assessing vaccine effectiveness.

Emerging Omicron Subvariants EG.5 and BA.2.86: Implications for COVID-19 Immunity and Surveillance

The SARS-CoV-2 virus, responsible for the COVID-19 pandemic, has continuously evolved since its emergence. Among its variants, the Omicron lineage has become globally dominant, displaying a diverse range of sublineages. Two significant sub lineages within Omicron are EG.5 and BA.2.8, which have gained attention due to their unique characteristics and potential implications. EG.5 is characterized by a constellation of mutations, including N501Y, L452R, and D614G. Similarly, BA.2.8 carries the L452Q and P681R mutations, which enhance its ability to evade antibodies elicited by prior infection or vaccination. Similar to those in the EG.5, the clinical severity and impact of BA.2.8 on public health measures are still being assessed. These sublineages, with their unique genetic profiles and transmissibility characteristics, pose challenges to virulence response efforts. Continued surveillance, genomic sequencing, and research are essential to understand their behavior, assess their impact, and inform public health strategies accordingly. By a comprehensive synthesis of the literature, genomic data, and epidemiological insights, this study provides an analysis of Omicron mutations’ transmission dynamics, and clinical implications associated with these variants. The significance of variant surveillance in informing public health responses to the COVID-19 pandemic is underscored, highlighting the critical role of genomic sequencing in tracking viral evolution and guiding interventions. This manuscript aimed to elucidate the mechanisms underlying variant emergence, assess vaccine effectiveness against emerging strains, and explore the broader implications for global public health. This study provides insights into vaccine-induced immunity and the potential impact of variants on vaccine efficacy. Overall, this communication aims to inform public health practitioners, policymakers, and researchers engaged in the battle against COVID-19, offering actionable insights to mitigate the spread of the virus and improve pandemic response strategies.

Anti-SARS-CoV-2 mRNA vaccination among patients living with SLE in Sweden: Coverage and clinical effectiveness.

To describe the uptake of anti-SARS-CoV2 vaccination in 2021 and investigate vaccine effectiveness in systemic lupus erythematosus (SLE) patients in Sweden. The cumulative incidence of first anti-SARS-CoV2 vaccination was estimated among SLE patients from the Swedish National Patient Register and matched comparators living in Sweden on January 1, 2021. To assess vaccine effectiveness, we included the individuals who received two doses of anti-SARS-CoV2 mRNA vaccines before year 2022, with no COVID-19 diagnosis code before the 2nd vaccine dose. Hospitalization rates with COVID-19 as main diagnosis during the year after second dose were compared between SLE patients and comparators in multivariable-adjusted marginal Cox models, overall and stratified by immunosuppressive treatment received during the year before second vaccine dose. Vaccination uptake was similar between SLE patients and comparators. By December 2021, 9% of both SLE and comparators had not received any vaccine doses. Among 5585 SLE patients and 37,102 comparators, 11 COVID-19 hospitalizations in the SLE group and 20 in the comparators occurred. SLE was associated with a higher risk of COVID-19 hospitalization (HR = 3.47, 95%CI 1.63-7.39). The HR was higher for immunosuppressive-treated SLE (7.03 95%CI 3.00-16.46) than for immunosuppressive-untreated (1.50 95%CI 0.34-6.60). Vaccination of immunosuppressive-untreated SLE patients had similar effectiveness as comparators. Anti-SARS-CoV2 vaccination coverage was similar between SLE patients and the general population in Sweden. Even though the incidence of post-vaccination COVID-19 hospitalization was very low, vaccine effectiveness was diminished in SLE patients compared to the general population and lowest in those treated with immunosuppressants.

Influenza epidemiology and vaccine effectiveness during the 2023/2024 season in Italy: A test-negative case-control study

In order to support policymakers in allocating resources, we aimed to assess vaccine effectiveness (VE) of inactivated influenza vaccines (IIVs) available for Italian adults in the 2023/2024 season. A hospital-based test-negative case-control study was conducted in Genoa between mid-October 2023 and mid-April 2024. Adult (≥18 years) inpatients with prescription of a polymerase chain reaction test for influenza were eligible. Of 1,664 adults analyzed, most (82%) of which were ≥65 years, 114 (6.9%) tested positive for influenza A. Most (92%) cases were caused by subclades 6B.1A.5a.2a and 6B.1A.5a.2a.1 of the A(H1N1)pdm09 subtype. In older adults aged ≥65 years vaccination was effective at 51% (95% CI: 8%, 74%) against any influenza A and 49% (95% CI: 2%, 73%) against A(H1N1)pdm09. Compared with non-vaccinated older adults, VE point estimates for the adjuvanted and, especially, high-dose IIVs were higher than those for the standard-dose non-adjuvanted IIV. The 2023/2024 seasonal influenza vaccination proved moderately effective in preventing hospitalization for laboratory-confirmed influenza. Being more appropriate for older adults, local policymakers and vaccinating physicians should maximize adoption of the enhanced IIVs.

A non-targeted metabolomics comparative study on plasma of pfizer and sinopharm COVID-19 vaccinated individuals, assessed by (TIMS-QTOF) mass spectrometry

COVID-19 is a highly contagious infectious disease that has posed a global threat, leading to a widespread pandemic characterized by multi-organ complications and failures. Aims: The present study was conducted to evaluate the impact of Pfizer and Sinopharm vaccines on metabolomic changes and their correlations with immune pathways. Main methods: The study used a cross-sectional design and implemented an untargeted metabolomics-based approach. Plasma samples were obtained from three groups: non-vaccinated participants, Sinopharm-vaccinated participants, and Pfizer-vaccinated participants. Comparative metabolomic analysis was conducted using TIMS-QTOF, and multiple t-tests with a 5 % false discovery rate (FDR) were performed using MetaboAnalyst software. Key findings: Out of the 105 metabolites detected, 72 showed statistically significant changes (p-value < 0.05) across the different groups. Notably, several metabolites such as neopterin, pyridoxal, and syringic acid were markedly altered in individuals vaccinated with Pfizer. Conversely, in the Sinopharm-vaccinated group, significant alterations were observed in sphinganine, neopterin, and sphingosine. These metabolites hold potential as biomarkers for evaluating vaccine efficacy. Additionally, both Pfizer and Sinopharm vaccinations were found to influence sphingolipid and histidine metabolisms compared to the control group. The Sinopharm group also displayed changes in lysine degradation relative to the control group. When comparing the enriched pathways between the Pfizer and Sinopharm-vaccinated groups, differences were observed in purine metabolism. Furthermore, alterations in tryptophan and vitamin B6 metabolism were noted when comparing the Pfizer-vaccinated group with both the control and Sinopharm-vaccinated groups. Significance: These findings highlight the importance of metabolomics in assessing vaccine effectiveness and identifying potential biomarkers for monitoring the efficacy of newly developed vaccines in a shorter timeframe.

Analysis of the implementation effect and evaluation of the vaccine protection effect of the live attenuated varicella vaccine program for school-age children in Bao’an district of Shenzhen,China

ABSTRACT The objective of the study is to analyze the implementation effect of the Live Attenuated Varicella Vaccine (VarV) Vaccination Program for eligible children in Bao’an District, Shenzhen, and evaluate the vaccine effectiveness. Children’s vaccination data was obtained from the Shenzhen Immunization Planning Information Management System, while varicella case data came from the China Disease Prevention and Control Information System. The Joinpoint regression method examined vaccination rate trends, and a retrospective cohort study assessed vaccine effectiveness. After program implementation, VarV vaccination rates significantly increased, surpassing provincial and national averages. Overall incidence declined 54.6% across age groups, with the largest reductions among 7- and 6-year-olds. One year post-vaccination, single-dose vaccine effectiveness was 91.1% (95% CI: 79.2% to 96.2%). However, two doses remained 91.4% effective(95% CI: 89.1% to 93.2%) after 7 years. Overall, Shenzhen’s VarV program achieved positive results. For children under six, routine immunization with two doses of VarV should be strengthened. Furthermore, we recommend that physicians conduct thorough inquiries to ascertain patients’ vaccination history and previous varicella infections. This will enable doctors to provide tailored vaccination recommendations based on comprehensive, practical evaluations.

Review of current perspectives and future outlook on bacterial disease prevention through vaccination in Asian seabass (Lates calcarifer).

Asian seabass, Lates calcarifer, is an important aquatic species in mariculture. Intensive farming of this species has faced episodes of bacterial diseases, including those due to vibriosis, scale drop, and muscle necrosis disease, big belly disease, photobacteriosis, columnaris, streptococcosis, aeromoniasis, and tenacibaculosis. Vaccination is one of the most efficient, non-antibiotic, and eco-friendly strategies for protecting fish against bacterial diseases, contributing to aquaculture expansion and ensuring food security. As of now, although numerous vaccines have undergone laboratory research, only one commercially available inactivated vaccine, suitable for both immersion and injection administration, is accessible for preventing Streptococcus iniae. Several key challenges in developing vaccines for Asian seabass must be addressed, such as the current limited understanding of immunological responses to vaccines, the costs associated with vaccine production, forms, and routes of vaccine application, and how to increase the adoption of vaccines by farmers. The future of vaccine development for the Asian seabass industry, therefore, is discussed with these key critical issues in mind. The focus is on improving our understanding of Asian seabass immunity, including maternal immunity, immunocompetence, and immune responses post-vaccination, as well as developing tools to assess vaccine effectiveness. The need for an alignment of fish vaccines with state-of-the-art vaccine technologies employed in human and terrestrial animal healthcare is also discussed. This review also discusses the necessity of providing locally-produced autogenous vaccines, especially for immersion and oral vaccines, to benefit small-scale fish farmers, and the potential benefits that might be extended through changes to current husbandry practices such as the vaccination of broodstock and earlier life stages of their off-spring.

Effectiveness of autumn 2023 COVID-19 vaccination and residual protection of prior doses against hospitalisation in England, estimated using a test-negative case-control study

IntroductionThe last COVID-19 vaccine offered to all adults in England became available from November 2021. The most recent booster programme commenced in September 2023. Bivalent BA.4-5 or monovalent XBB.1.5 boosters were given. During the study period, the JN.1 variant became dominant in England. MethodsVaccine effectiveness against hospitalisation was estimated throughout using the test-negative case-control study design where positive PCR tests from hospitalised individuals are cases and comparable negative PCR tests are controls. Multivariable logistic regression was used to assess vaccine effectiveness against hospitalisation with the test result as the outcome, vaccination status as the primary exposure variable of interest and confounder adjustment. ResultsThere was no evidence of residual protection for boosters given as part of previous campaigns. There were 28,916 eligible tests included to estimate the effectiveness of the autumn 2023 boosters in those aged 65 years and older. VE peaked at 50.6% (95% CI: 44.2-56.3%) after 2-4 weeks, followed by waning to 13.6% (95% CI: -11.7-33.2%). Estimates were generally higher for the XBB.1.5 booster than the BA.4-5 booster, but this difference was not statistically significant. Point estimates were highest against XBB sub-lineages. Effectiveness was lower against both JN.1 and EG.5.1 variants with confidence intervals non-overlapping with the effectiveness of the XBB sub-lineages at 2-4 weeks for EG.5.1 where VE was 44.5% (95% CI: 20.2- 61.4%) and at 5-9 weeks for JN.1 where VE was 26.4% (95%CI: -3.4-47.6%). ConclusionsThe recent monovalent XBB.1.5 and bivalent BA.4-5 boosters provided comparable and good protection against hospitalisation, however there was evidence of lower VE against hospitalisation of these boosters against JN.1.

Effectiveness of BNT162b2 COVID-19 primary series vaccination in children aged 5–17 years in the United States: a cohort study

BackgroundCOVID-19 vaccines are authorized for use in children in the United States; real-world assessment of vaccine effectiveness in children is needed. This study’s objective was to estimate the effectiveness of receiving a complete primary series of monovalent BNT162b2 (Pfizer-BioNTech) COVID-19 vaccine in US children.MethodsThis cohort study identified children aged 5–17 years vaccinated with BNT162b2 matched with unvaccinated children. Participants and BNT162b2 vaccinations were identified in Optum and CVS Health insurance administrative claims databases linked with Immunization Information System (IIS) COVID-19 vaccination records from 16 US jurisdictions between December 11, 2020, and May 31, 2022 (end date varied by database and IIS). Vaccinated children were followed from their first BNT162b2 dose and matched to unvaccinated children on calendar date, US county of residence, and demographic and clinical factors. Censoring occurred if vaccinated children failed to receive a timely dose 2 or if unvaccinated children received any dose. Two COVID-19 outcome definitions were evaluated: COVID-19 diagnosis in any medical setting and COVID-19 diagnosis in hospitals/emergency departments (EDs). Propensity score-weighted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated with Cox proportional hazards models, and vaccine effectiveness (VE) was estimated as 1 minus HR. VE was estimated overall, within age subgroups, and within variant-specific eras. Sensitivity, negative control, and quantitative bias analyses evaluated various potential biases.ResultsThere were 453,655 eligible vaccinated children one-to-one matched to unvaccinated comparators (mean age 12 years; 50% female). COVID-19 hospitalizations/ED visits were rare in children, regardless of vaccination status (Optum, 41.2 per 10,000 person-years; CVS Health, 44.1 per 10,000 person-years). Overall, vaccination was associated with reduced incidence of any medically diagnosed COVID-19 (meta-analyzed VE = 38% [95% CI, 36–40%]) and hospital/ED–diagnosed COVID-19 (meta-analyzed VE = 61% [95% CI, 56–65%]). VE estimates were lowest among children 5–11 years and during the Omicron-variant era.ConclusionsReceipt of a complete BNT162b2 vaccine primary series was associated with overall reduced medically diagnosed COVID-19 and hospital/ED–diagnosed COVID-19 in children; observed VE estimates differed by age group and variant era.RegistrationThe study protocol was publicly posted on the BEST Initiative website (https://bestinitiative.org/wp-content/uploads/2022/03/C19-VX-Effectiveness-Protocol_2022_508.pdf).

P021 Uptake, safety, and effectiveness of pneumococcal vaccination in adults with immune mediated inflammatory diseases: a UK wide study using data from the Clinical Practice Research Datalink

Abstract Background/Aims The safety and effectiveness of pneumococcal vaccine in people with immune mediated inflammatory diseases (IMIDs) is not known, which may contribute to suboptimal uptake. We investigated UK wide pneumococcal vaccine uptake in adults with IMIDs, the association between pneumococcal vaccination and disease flares, and the effectiveness of pneumococcal vaccine in preventing pneumonia in this at-risk population. Methods Adults with incident rheumatoid arthritis (RA), inflammatory bowel disease (IBD), systemic lupus erythematosus (SLE) and spondyloarthritis (SpA) prior to 31st August 2018 in the Clinical Practice Research Datalink (CPRD) Gold were included. The study was approved by CPRD research data governance (Reference 21_000614). We calculated the proportion of patients vaccinated against pneumococcal pneumonia. To investigate the association between vaccination and IMID flare, we employed a self-controlled case series analysis, adjusted for season. The study period was up-to six-month before and six-month after the date of pneumococcal vaccination. This period was partitioned into induction (14 days pre-vaccination) and exposed periods (up-to 90 days post vaccination) with the remaining time considered unexposed. Incidence rate ratios (IRR) and 95% CI were calculated. We conducted a multivariable nested case-control study to assess vaccine effectiveness. Cases were patients hospitalised with pneumonia and were matched to up to ten controls for age and sex. Multivariable conditional logistic regression was used to calculate odds ratio (OR) and 95% CI. Results We included 32,277 IMID patients: 14,151 with RA, 13,631 with IBD, 3,804 with SpA and 691 with SLE. Overall uptake of pneumococcal vaccination was 50% (95% CI 49.4% -50.5%). Vaccination uptake was significantly lower in the under 45-year-olds, in patients with IBD and in those without additional indication for vaccination at 29.7%, 38.4%, 42.7% respectively. In the safety study, data for 1001, 854, 424 vaccinated patients with primary care consultations for joint pain, AIRD flare, and IBD flare respectively were included. Vaccination against pneumococcal pneumonia was not associated with AIRD flare (IRR (95% CI) 1.07 (0.93-1.22)), primary care consultations for joint pain (IRR (95% CI) 0.95 (0.83-1.10)), and IBD flare (IRR (95% CI) 0.82 (0.64-1.06)) in the 90-days post vaccination. The vaccine effectiveness study included 25,707 patients, either with (n = 2,771) or without (n = 22,936) a hospitalisation record for pneumonia after IMID diagnosis. Patients hospitalised for pneumonia compared with their matched controls, had higher odds of current smoking, deprivation, corticosteroid prescriptions, additional indication for vaccination, primary care consultations, hospital admissions and prescriptions. In the multivariable adjusted model, pneumococcal vaccination was associated with reduced odds of hospitalisation for pneumonia (OR (95% CI) 0.88 (0.78-0.98). Conclusion The uptake of pneumococcal vaccine is low in IMID patients. Pneumococcal vaccination is not associated with IMID flare and is protective against pneumonia. These findings call for promotion of pneumococcal vaccination in IMID by health professionals. Disclosure G. Nakafero: None. M.J. Grainge: None. C.D. Mallen: Grants/research support; NIHR, MRC, Versus Arthritis and BMS. T. Card: None. J.S. Nguyen Van-Tam: Consultancies; CSL Seqirus and Moderna. Royalties; AstraZeneca and Sanofi Pasteur. A. Abhishek: Consultancies; NGM Bio, Limbic and Inflazome.. Royalties; UpToDate, Springer, Cadilla Pharmaceuticals.. Grants/research support; AstraZeneca and Oxford Immunotech..

Overview of JN.1 the variant of interest: strengths, weaknesses, opportunities, and threats analysis

Amidst the ongoing global battle against the COVID-19 pandemic, the World Health Organization (WHO) emphasizes monitoring variants of interest (VOIs) of the SARS-CoV-2 virus. The JN.1 variant, initially considered within the framework of BA.2.86, has rapidly gained global prevalence, prompting its reclassification as an independent VOI. This study assesses the strengths, weaknesses, opportunities, and threats (SWOT) analysis of the JN.1 variant. A literature review from PubMed, and expert opinions from newspaper articles were utilized for information collection. The study incorporates a comprehensive SWOT analysis, associated with the JN.1 variant. The JN.1 variant's global dominance is marked by exponential increases in COVID-19 cases, impacting healthcare systems. While strengths include global guidance, vaccine effectiveness, and a robust surveillance system, weaknesses encompass wastewater analysis, seasonal impacts, and immune escape capabilities. Opportunities lie in continuous vaccination campaigns, monitoring, research, vaccine adaptation, and adaptive strategies. Threats include co-circulation with respiratory diseases, lower antibody responses, and potential global spread. The study underscores the importance of clear public communication, continuous surveillance, and research efforts in addressing the challenges posed by the JN.1 variant. Recommendations include assessing vaccine effectiveness, updating strategies and fostering global collaboration for a more effective response.

Understanding the time-driven shifts of vaccine effectiveness against any and severe COVID-19 before and after the surge of Omicron variants within 2.5 years of vaccination: A meta-regression

ObjectivesThe COVID-19 pandemic required rapid development of vaccines within a short period of time which did not allow to assess vaccine effectiveness (VE) in the long-term. MethodsA computerized literature search was undertaken to identify eligible studies, with no language restrictions, published between 1 December 2020 and 30 June 2023. ResultsOut of a total of 27,597 publications, 761 studies were included. Early VE of 87.2% decreased to 55.1% after 9 months among populations fully immunized not only with mRNA (proxy mRNA) vaccines, and 66.3% decreased to 23.5% in populations immunized exclusively with non-mRNA vaccines. Protection against severe COVID-19 declined to 80.9% for proxy mRNA vaccines and 67.2% for non-mRNA vaccines. Omicron variants significantly diminished VE. Within 6-8 months of receiving a single booster of an mRNA vaccine, VE declined to 14.0% and 67.7% for any and severe COVID-19, respectively. Multiple mRNA booster doses restored protection that declined to 29.5% and 70.6% for any and severe COVID-19, respectively, within 5-7 months. ConclusionOutcomes of this meta-regression underscore the evolving nature of COVID-19 in response to vaccination, dosing schedules, and emerging variants, and provide crucial insights for public health interventions and vaccination strategies.

Prediction of effectiveness of universal rotavirus vaccination in Southwestern Vietnam based on a dynamic mathematical model

Vaccinating young children against rotavirus (RV) is a promising preventive strategy against rotavirus gastroenteritis (RVGE). We evaluated the relative risk reduction of RVGE induced by universal vaccination in Vietnam through dynamic model analysis. We developed an age-stratified dynamic Vaccinated-Susceptible-Infectious-Recovered-Susceptible model to analyze RV transmission and assess vaccine effectiveness (VE). We assumed 3 different vaccine efficacies: 55%, 70%, and 85%. For model calibration, we used a database of patients under 5 years of age admitted to Ho Chi Minh No.1 Hospital with RVGE between January 2013 and December 2018. Assuming a vaccination rate of 95%, the number of RVGE hospitalizations after 5 years from universal RV vaccination decreased from 92,502 cases to 45,626 with 85% efficacy, to 54,576 cases with 70% efficacy, and to 63,209 cases with 55% efficacy. Additionally, RVGE hospitalizations after 10 years decreased from 177,950 to 89,517 with 85% efficacy and to 121,832 cases with 55% efficacy. The relative risk reductions of RVGE after 10 years were 49.7% with 85% efficacy, 40.6% with 70% efficacy, and 31.5% with 55% efficacy. The VE was 1.10 times (95% CI, 1.01–1.22) higher in the 4-months to 1-year-old age group than in the other age groups (P = 0.038), when applying 85% efficacy with 95% coverage. In conclusion, despite its relatively lower efficacy compared to high-income countries, RV vaccination remains an effective intervention in Southwestern Vietnam. In particular, implementing universal RV vaccination with higher coverage would result in a decrease in RVGE hospitalizations among Vietnamese children under 5 years of age.