Assessment of potential adverse events following the 2022-2023 seasonal influenza vaccines among U.S. adults aged 65 years and older.

BACKGROUND: While safety of influenza vaccines is well-established, some studies have suggested potential associations between influenza vaccines and certain adverse events (AEs). This study examined the safety of the 2022-2023 influenza vaccines among U.S. adults ≥ 65 years. METHODS: A self-controlled case series compared incidence rates of anaphylaxis, encephalitis/encephalomyelitis, Guillain-Barré Syndrome (GBS), and transverse myelitis following 2022-2023 seasonal influenza vaccinations (i.e., any, high-dose or adjuvanted) in risk and control intervals among Medicare beneficiaries ≥ 65 years. We used conditional Poisson regression to estimate incidence rate ratios (IRRs) and 95 % confidence intervals (CIs) adjusted for event-dependent observation time and seasonality. Analyses also accounted for uncertainty from outcome misclassification where feasible. For AEs with any statistically significant associations, we stratified results by concomitant vaccination status. RESULTS: Among 12.7 million vaccine recipients, we observed 76 anaphylaxis, 276 encephalitis/encephalomyelitis, 134 GBS and 75 transverse myelitis cases. Only rates of anaphylaxis were elevated in risk compared to control intervals. With all adjustments, an elevated, but non-statistically significant, anaphylaxis rate was observed following any (IRR: 2.40, 95% CI: 0.96-6.03), high-dose (IRR: 2.31, 95% CI: 0.67-7.91), and adjuvanted (IRR: 3.28, 95% CI: 0.71-15.08) influenza vaccination; anaphylaxis IRRs were 2.54 (95% CI: 0.49-13.05) and 1.64 (95% CI: 0.38-7.05) for persons with and without concomitant vaccination, respectively. CONCLUSIONS: Rates of encephalitis/encephalomyelitis, GBS, or transverse myelitis were not elevated following 2022-2023 seasonal influenza vaccinations among U.S. adults ≥ 65 years. There was an increased rate of anaphylaxis following influenza vaccination that may have been influenced by concomitant vaccination.

Immunogenicity and safety of concomitant administration of recombinant COVID-19 vaccine and quadrivalent inactivated influenza vaccine in Chinese adults: An open-label, randomized, controlled trial.

The immunogenicity and safety of the concomitant administration of recombinant COVID-19 vaccine and quadrivalent inactivated influenza vaccine (Split Virion) (QIIV) in Chinese adults are unclear. In this open-label, randomized controlled trial, participants aged ≥ 18 years were recruited. Eligible healthy adults were randomly assigned (1:1) to receive QIIV at the same time as the first dose of COVID-19 vaccine (simultaneous-group) or 14 days after the second dose of COVID-19 vaccine (non-simultaneous-group). The primary outcome was to compare the difference in immunogenicity of QIIV (H1N1, H3N2, Yamagata, and Victoria) between the two groups. A total of 299 participants were enrolled, 149 in the simultaneous-group and 150 in the non-simultaneous-group. There were no significant differences in geometric mean titer (GMT) [H1N1: 386.4 (95%CI: 299.2-499.0) vs. 497.4 (95%CI: 377.5-655.3); H3N2: 66.9 (95%CI: 56.1-79.8) vs. 81.4 (95%CI: 67.9-97.5); Yamagata: 95.6 (95%CI: 79.0-115.8) vs. 74.3 (95%CI: 58.6-94.0); and Victoria: 48.5 (95%CI: 37.6-62.6) vs. 65.8 (95%CI: 49.0-88.4)] and seroconversion rate (H1N1: 87.5% vs. 90.1%; H3N2: 58.1% vs. 62.0%; Yamagata: 75.0% vs. 64.5%; and Victoria: 55.1% vs. 62.8%) of QIIV antibodies between the simultaneous and non-simultaneous groups. For the seroprotection rate of QIIV antibodies, a higher seroprotection rate of Yamagata antibody was observed only in the simultaneous-group than in the non-simultaneous-group [86.0% vs. 76.0%, p = .040]. In addition, no significant difference in adverse events was observed between the two groups (14.2% vs. 23.5%, p = .053). In conclusion, no immune interference or safety concerns were found for concomitant administration of COVID-19 vaccine with QIIV in adults aged ≥ 18 years.

Safety of concomitant administration of 23-valent polysaccharide pneumococcal vaccine and influenza vaccine among the elderly.

BACKGROUND: The current recommendation for the elderly is to receive both a single dose 23-valent pneumococcal polysaccharide vaccine (PPSV-23) and an annual inactivated influenza vaccine. There is a lack of post-marketing safety studies on concomitant vaccination using real-world data. We aimed to evaluate the safety of administering PPSV-23 and influenza vaccine concomitantly versus sequentially. METHODS: We performed a retrospective cohort study using a linked database that combines vaccination registry from the Korea Disease Control and Prevention Agency and claims data from the National Health Insurance Service. The study population included all those aged over 65 who received PPSV-23 at least once from Jan 1, 2016, to Dec 31, 2020. This study evaluated the 16 prespecified events of interest. Concomitant vaccination was defined as receiving both PPSV-23 and influenza vaccine on the same day. For sequential vaccination, we defined it as receiving influenza vaccination during the period from 30 to 365 days prior to the date of PPSV-23 injection. We performed 1:4 propensity score matching and estimated adjusted incidence rate ratio (aIRR) with a 95 % confidence interval (CI) using conditional Poisson regression. RESULTS: Of the 2,885,144 elderly patients who received PPSV-23 vaccination at least once from Jan 1, 2016, to Dec 31, 2020, a total 87,899 were included in the concomitant vaccination group and 1,200,091 were included in the sequential vaccination group. After adjusting for confounders, the concomitant group exhibited a significantly lower risk of allergic reactions (aIRR: 0.71, 95 % CI: 0.58-0.87), neuritis (aIRR: 0.72, 95 % CI: 0.57-0.91), and pneumonia (aIRR: 0.85, 95 % CI: 0.80-0.90), while demonstrating significantly higher risks of paralysis (aIRR: 1.63, 95 % CI: 1.05-2.52) compared to the sequential group. CONCLUSIONS: Concomitant administration of PPSV-23 and influenza vaccine in the elderly was not associated with a higher risk of most prespecified adverse events (AEs) compared to sequential vaccination. This study supports the safety of concomitant administration of PPSV-23 and influenza vaccine.

Enhanced passive safety surveillance of high-dose and standard-dose quadrivalent inactivated split-virion influenza vaccines in Germany and Finland during the 2022/23 influenza season.

Enhanced Passive Safety Surveillance (EPSS) was conducted for quadrivalent inactivated split-virion influenza vaccines (IIV4) in Germany (high dose [HD]) and Finland (standard dose [SD]) for the northern hemisphere (NH) 2022/23 influenza season. The primary objective was to assess adverse events following immunization (AEFI) occurring ≤7 days post-vaccination. In each country, the EPSS was conducted at the beginning of the NH influenza season. Exposure information was documented using vaccination cards (VC), and AEFI were reported via an electronic data collection system or telephone. AEFI were assessed by seriousness and age group (Finland only). The vaccinee reporting rate (RR) was calculated as the number of vaccinees reporting ≥ 1 AEFI divided by the total vaccinees. In Germany, among 1041 vaccinees, there were 31 AEFI (ten vaccinees) during follow-up, including one serious AEFI. Of 16 AEFI (six vaccinees) with reported time of onset, 15 occurred ≤7 days post-vaccination (RR 0.58%, 95% confidence interval [CI] 0.21, 1.25), which was lower than the 2021/22 season (RR 1.88%, 95% CI: 1.10, 3.00). In Finland, among 1001 vaccinees, there were 142 AEFI (51 vaccinees) during follow-up, none of which were serious. Of 133 AEFI (48 vaccinees) with time of onset reported, all occurred ≤7 days post-vaccination (RR 4.80%, 95% CI: 3.56, 6.31), which was similar to the 2021/22 season (RR 4.90%, 95% CI: 3.65, 6.43). The EPSS for HD-IIV4 and for SD-IIV4 in the 2022/23 influenza season did not suggest any clinically relevant changes in safety beyond what is known/expected for IIV4s.

Reports of COVID-19 Vaccine Adverse Events in Predominantly Republican vs Democratic States.

Importance: Antivaccine sentiment is increasingly associated with conservative political positions. Republican-inclined states exhibit lower COVID-19 vaccination rates, but the association between political inclination and reported vaccine adverse events (AEs) is unexplored. Objective: To assess whether there is an association between state political inclination and the reporting rates of COVID-19 vaccine AEs. Design, Setting, and Participants: This cross-sectional study used the AE reports after COVID-19 vaccination from the Vaccine Adverse Event Reporting System (VAERS) database from 2020 to 2022, with reports after influenza vaccines from 2019 to 2022 used as a reference. These reports were examined against state-level percentage of Republican votes in the 2020 US presidential election. Exposure: State-level percentage of Republican votes in the 2020 US presidential election. Main Outcomes and Measures: Rates of any AE among COVID-19 vaccine recipients, rates of any severe AE among vaccine recipients, and the proportion of AEs reported as severe. Results: A total of 620 456 AE reports (mean [SD] age of vaccine recipients, 51.8 [17.6] years; 435 797 reports from women [70.2%]; a vaccine recipient could potentially file more than 1 report, so reports are not necessarily from unique individuals) for COVID-19 vaccination were identified from the VAERS database. Significant associations between state political inclination and state AE reporting were observed for all 3 outcomes: a 10% increase in Republican voting was associated with increased odds of AE reports (odds ratio [OR], 1.05; 95% CI, 1.05-1.05; P < .001), severe AE reports (OR, 1.25; 95% CI, 1.24-1.26; P < .001), and the proportion of AEs reported as severe (OR, 1.21; 95% CI, 1.20-1.22; P < .001). These associations were seen across all age strata in stratified analyses and were more pronounced among older subpopulations. Conclusions and Relevance: This cross-sectional study found that the more states were inclined to vote Republican, the more likely their vaccine recipients or their clinicians reported COVID-19 vaccine AEs. These results suggest that either the perception of vaccine AEs or the motivation to report them was associated with political inclination.

An 8-Year Prospective, Observational, Multi-centre Post-Marketing Safety Surveillance Study Conducted in South Korea (2014-2022) Following the Introduction of GSK's Inactivated Quadrivalent Seasonal Influenza Vaccine (Fluarix Tetra) for Subjects Aged 6 Months and Older.

INTRODUCTION: Seasonal influenza is associated with substantial public health burden. The objective of this study was to assess the safety of inactivated quadrivalent seasonal influenza vaccine (IIV4, Fluarix Tetra, GSK, Belgium) in subjects aged ≥ 6 months in Korea. METHODS: This prospective, observational, non-comparative, multi-centre post-marketing surveillance study was conducted in Korea in subjects aged ≥ 3 years for 6 years (2014-2020) and extended to subjects aged 6-35 months for 4 years (2018-2022). Subjects received IIV4 in routine clinical practice according to local prescribing information. Adverse events (AEs) were recorded over 21 days post-vaccination. RESULTS: The group aged ≥ 3 years included 701 subjects (mean 31.97 years, range 3-86 years, 46.36% male), and the group aged 6-35 months included 687 subjects (mean 16.31 months, 47.02% male). In the group aged ≥ 3 years, 98 subjects (13.98%) reported 140 AEs, of which 42 events in 34 subjects (4.85%) were adverse reactions to vaccine (ARVs). Most of the ARVs were expected, mainly administration site reactions. There were seven mild unexpected ARVs. In the group aged 6-35 months, 248 AEs were reported in 149/687 subjects (21.69%). ARVs were reported in 25/687 subjects (3.64%, 29 events); one was considered unexpected. There were five serious AEs overall, none of which were considered related. CONCLUSION: No safety concerns were found during this surveillance study of IIV4 in subjects aged ≥ 6 months in Korea. The findings of this study suggest IIV4 is safe and well tolerated for use in all age groups with a vaccine indication.

Seasonal influenza is associated with over 5000 deaths annually in Korea, mainly in older adults. Annual vaccination is the most effective way of preventing seasonal influenza. The influenza virus strains in the vaccine are updated each year as the strains circulating change constantly. Monitoring of any unwanted medical incidents (adverse events) after vaccination is required to help assess vaccine safety. In this study, we monitored adverse events reported within 21 days of administration of Fluarix Tetra seasonal influenza vaccine (IIV4) in participants aged 6 months and older in Korea over a period of 4­6 years. Of the participants aged ≥ 3 years, 98 (14%) reported 140 adverse events, most commonly infections and infestations (most commonly nasopharyngitis such as the common cold), or general disorders and administration site conditions (most commonly pain or swelling at the injection site). In the participants aged 6­35 months, 149 (22%) reported 248 adverse events, also most commonly infections and infestations (such as the common cold) or general disorders and administration site conditions (most commonly fever or swelling at the injection site). There were five serious adverse events in total (adverse events that are life threatening or require hospitalization), but none of them were related to IIV4. In this study, we did not find any safety concerns for IIV4 in participants aged ≥ 6 months in Korea. The findings of this study suggest IIV4 is safe and well tolerated in all age groups with a vaccine indication.

Stroke Risk After COVID-19 Bivalent Vaccination Among US Older Adults.

Importance: In January 2023, the US Centers for Disease Control and Prevention and the US Food and Drug Administration noted a safety concern for ischemic stroke among adults aged 65 years or older who received the Pfizer-BioNTech BNT162b2; WT/OMI BA.4/BA.5 COVID-19 bivalent vaccine. Objective: To evaluate stroke risk after administration of (1) either brand of the COVID-19 bivalent vaccine, (2) either brand of the COVID-19 bivalent plus a high-dose or adjuvanted influenza vaccine on the same day (concomitant administration), and (3) a high-dose or adjuvanted influenza vaccine. Design, Setting, and Participants: Self-controlled case series including 11 001 Medicare beneficiaries aged 65 years or older who experienced stroke after receiving either brand of the COVID-19 bivalent vaccine (among 5 397 278 vaccinated individuals). The study period was August 31, 2022, through February 4, 2023. Exposures: Receipt of (1) either brand of the COVID-19 bivalent vaccine (primary) or (2) a high-dose or adjuvanted influenza vaccine (secondary). Main Outcomes and Measures: Stroke risk (nonhemorrhagic stroke, transient ischemic attack, combined outcome of nonhemorrhagic stroke or transient ischemic attack, or hemorrhagic stroke) during the 1- to 21-day or 22- to 42-day risk window after vaccination vs the 43- to 90-day control window. Results: There were 5 397 278 Medicare beneficiaries who received either brand of the COVID-19 bivalent vaccine (median age, 74 years [IQR, 70-80 years]; 56% were women). Among the 11 001 beneficiaries who experienced stroke after receiving either brand of the COVID-19 bivalent vaccine, there were no statistically significant associations between either brand of the COVID-19 bivalent vaccine and the outcomes of nonhemorrhagic stroke, transient ischemic attack, nonhemorrhagic stroke or transient ischemic attack, or hemorrhagic stroke during the 1- to 21-day or 22- to 42-day risk window vs the 43- to 90-day control window (incidence rate ratio [IRR] range, 0.72-1.12). Among the 4596 beneficiaries who experienced stroke after concomitant administration of either brand of the COVID-19 bivalent vaccine plus a high-dose or adjuvanted influenza vaccine, there was a statistically significant association between vaccination and nonhemorrhagic stroke during the 22- to 42-day risk window for the Pfizer-BioNTech BNT162b2; WT/OMI BA.4/BA.5 COVID-19 bivalent vaccine (IRR, 1.20 [95% CI, 1.01-1.42]; risk difference/100 000 doses, 3.13 [95% CI, 0.05-6.22]) and a statistically significant association between vaccination and transient ischemic attack during the 1- to 21-day risk window for the Moderna mRNA-1273.222 COVID-19 bivalent vaccine (IRR, 1.35 [95% CI, 1.06-1.74]; risk difference/100 000 doses, 3.33 [95% CI, 0.46-6.20]). Among the 21 345 beneficiaries who experienced stroke after administration of a high-dose or adjuvanted influenza vaccine, there was a statistically significant association between vaccination and nonhemorrhagic stroke during the 22- to 42-day risk window (IRR, 1.09 [95% CI, 1.02-1.17]; risk difference/100 000 doses, 1.65 [95% CI, 0.43-2.87]). Conclusions and Relevance: Among Medicare beneficiaries aged 65 years or older who experienced stroke after receiving either brand of the COVID-19 bivalent vaccine, there was no evidence of a significantly elevated risk for stroke during the days immediately after vaccination.

AE-GPT: Using Large Language Models to extract adverse events from surveillance reports-A use case with influenza vaccine adverse events.

Though Vaccines are instrumental in global health, mitigating infectious diseases and pandemic outbreaks, they can occasionally lead to adverse events (AEs). Recently, Large Language Models (LLMs) have shown promise in effectively identifying and cataloging AEs within clinical reports. Utilizing data from the Vaccine Adverse Event Reporting System (VAERS) from 1990 to 2016, this study particularly focuses on AEs to evaluate LLMs' capability for AE extraction. A variety of prevalent LLMs, including GPT-2, GPT-3 variants, GPT-4, and Llama2, were evaluated using Influenza vaccine as a use case. The fine-tuned GPT 3.5 model (AE-GPT) stood out with a 0.704 averaged micro F1 score for strict match and 0.816 for relaxed match. The encouraging performance of the AE-GPT underscores LLMs' potential in processing medical data, indicating a significant stride towards advanced AE detection, thus presumably generalizable to other AE extraction tasks.

Eficacia y seguridad de la vacunación antigripal pediátrica: una revisión sistemática / Efficacy and safety of pediatric flu vaccination: a systematic review

Introducción. Los a corren un mayor riesgo de infección por influenza en comparación con la población general. La Organización Mundial la Salud y las recomendaciones del Comité Asesor de Vacunas de la Asociación Española de Pediatría contemplan la vacunación anual como la forma más eficaz de prevenir la enfermedad. Por lo tanto, el propósito de esta revisión fue actualizar la información sobre eficacia y seguridad en la vacuna antigripal en niños y adolescentes. Material y métodos. Una búsqueda en cuatro bases de datos electrónicas (Scopus, Cumulative Index to Nursing and Allied Health Literature, MedLine / PubMed, Google Scholar y Cochrane), así como una búsqueda manual para identificar investigaciones originales publicadas entre 2012 y 2022. Se adoptaron las directrices de análisis (PRISMAcR) como elemento de informe preferido para revisiones sistemáticas. Resultados. Se incluyeron siete artículos de investigación originales donde se identificaron dos temas de la vacunación antigripal en niños/adolescentes sanos y con patologías. La eficacia (entre un 30% y un 80% aproximadamente) varió en función de la vacuna utilizada y los subtipos circulantes. La mayoría de las reacciones adversas fueron de intensidad leve y el evento adverso local más común informado fue dolor en el sitio de la inyección. Conclusiones. Destacamos positivamente la seguridad de la vacunación antigripal pediátrica en los estudios analizados, por el contrario, con respecto a la eficacia de la vacunación antigripal, observamos una amplia variabilidad de resultados. Existe una clara necesidad de seguir realizando estudios de eficacia y seguridad en el niño. (AU)

Introduction. Children are at a higher risk of influenza infection compared to the general population. The World Organization Health and recommendations of the Vaccine Advisory Committee of the Spanish Association of Pediatrics contemplate annual vaccination as the most effective way to prevent the disease. Therefore, the purpose of this review was to update information on efficacy and safety in the anti -shed vaccine in children and adolescents. Material and methods. A search in four electronic databases (Scopus, Cumulative Index to Nursing and Allied Health Literature, Medline / Pubmed, Google Scholar and Cochrane), as well as a manual search to identify original research published between 2012 and 2022. The guidelines of ANALYSIS (PRISMACR) as a preferred report element for systematic reviews. Results. Seven original research articles were included where two issues of antigripal vaccination were identified in healthy children/adolescents and with pathologies. The efficacy (between approximately 30% and 80%) varied depending on the vaccine used and circulating subtypes. Most adverse reactions were mild intensity, and the most common local adverse event was pain in the injection site. Conclusions. We positively highlight the safety of pediatric flu vaccination in analyzed studies, on the contrary, with respect to the efficacy of flu vaccination, we observe a wide variability of results. There is a clear need to continue conducting efficacy and safety studies in the child. (AU)

Safety of Simultaneous Administration of Bivalent mRNA COVID-19 and Influenza Vaccines in the Vaccine Adverse Event Reporting System (VAERS).

INTRODUCTION: Bivalent mRNA coronavirus disease 2019 (COVID-19) vaccines may be simultaneously administered with other recommended vaccines, including seasonal influenza vaccines. However, few studies have evaluated the safety of co-administration of bivalent mRNA COVID-19 and seasonal influenza vaccines. OBJECTIVE: The aim was to describe reports to the Vaccine Adverse Event Reporting System (VAERS) after co-administration of bivalent mRNA COVID-19 and seasonal influenza vaccines. METHODS: We searched the VAERS database for reports of adverse events (AEs) following co-administration of bivalent mRNA COVID-19 and seasonal influenza vaccines during the period of September 1, 2022-March 31, 2023. We assessed the characteristics of these reports and described the most frequently reported AEs. Clinicians reviewed available medical records for reports of serious AEs and adverse events of special interest (AESI). RESULTS: During the period of 1 September 2022 through 31 March 2023, VAERS received 3689 reports of AEs following co-administration of bivalent mRNA COVID-19 and seasonal influenza vaccines. The median age of vaccinees was 59 years (interquartile range 39, 70 years); 342 reports (9.3%) were classified as serious. The most common AEs among non-serious reports were severe-acute-respiratory-syndrome-related coronavirus (SARS-CoV-2) infection (785, 23.5%), cough (592, 17.7%), and fatigue (568, 17.0%). The most common AEs among serious reports were Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection (88, 25.7%), dyspnea (81, 23.7%), and condition aggravated (55, 16.1%). DISCUSSION: Reports of AEs following co-administration of bivalent mRNA COVID-19 and seasonal influenza vaccines did not reveal any unusual or unexpected patterns of AEs. Increased reporting of certain events (e.g., COVID-19) was expected due to Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC) reporting requirements. CDC and FDA will continue to monitor the safety of co-administration of mRNA COVID-19 and seasonal influenza vaccines.

Immunogenicity and safety of a quadrivalent recombinant influenza vaccine manufactured in Iran (FluGuard) in volunteers aged 18-60 years: A double-blind, non-inferiority, randomized controlled trial.

BACKGROUND: This study aimed to evaluate the non-inferiority of the FluGuard (a quadrivalent recombinant vaccine manufactured by Nivad Pharmed Salamat Company in Iran) by comparing its immunogenicity and safety with Vaxigrip Tetra (a quadrivalent inactivated vaccine manufactured by Sanofi Pasteur in France). MATERIALS AND METHODS: In this double-blind, randomized controlled trial, eligible volunteers aged 18-60 were randomized to receive either FluGuard or Vaxigrip Tetra vaccines. Immunogenicity was evaluated using the Hemagglutination Inhibition (HAI) assay and reported with the geometric mean titer (GMT), seroprotection, and seroconversion. In addition, vaccine safety was assessed by interviewing participants through phone calls. RESULTS: Out of 110 randomized volunteers, 51 and 53 were entered into the final analysis in the Vaxigrip and FluGuard groups, respectively. Vaxigrip had a higher seroprotection rate for the H1N1 strain compared with FluGuard (98 % vs. 91 %). Besides, FluGuard had higher seroprotection rates for H3N2 (74 % vs. 69 %), B-Yamagata (87 % vs. 84 %), and B-Victoria (66 % vs. 41 %) strains compared with Vaxigrip. In all four strains, FluGuard was non-inferior to Vaxigrip with the upper bounds of the 95 % CI on the ratio of the GMTs < 1.5: H1N1 (1.25), H3N2 (0.94), B-Yamagata (0.62), and B-Victoria (0.59). Furthermore, FluGuard was non-inferior to Vaxigrip with the upper bounds of the 95 % CI on the difference between the seroconversion rates < 10 %: H1N1 (2 %), H3N2 (10 %), B-Yamagata (-10 %), and B-Victoria (-29 %). The prevalence of solicited adverse drug reactions did not differ between groups. Furthermore, participants did not experience serious adverse events. CONCLUSION: Our findings support the non-inferiority of the FluGuard vaccine to the Vaxigrip vaccine regarding immunogenicity and safety. CLINICAL TRIAL REGISTRY: The study protocol was approved by the Iranian Registry of Clinical Trials (IRCT20210901052358N5).

Recombinant parainfluenza virus 5 expressing clade 2.3.4.4b H5 hemagglutinin protein confers broad protection against H5Ny influenza viruses.

The global circulation of clade 2.3.4.4b H5Ny highly pathogenic avian influenza viruses (HPAIVs) in poultry and wild birds, increasing mammal infections, continues to pose a public health threat and may even form a pandemic. An efficacious vaccine against H5Ny HPAIVs is crucial for emergency use and pandemic preparedness. In this study, we developed a parainfluenza virus 5 (PIV5)-based vaccine candidate expressing hemagglutinin (HA) protein of clade 2.3.4.4b H5 HPAIV, termed rPIV5-H5, and evaluated its safety and efficacy in mice and ferrets. Our results demonstrated that intranasal immunization with a single dose of rPIV5-H5 could stimulate H5-specific antibody responses, moreover, a prime-boost regimen using rPIV5-H5 stimulated robust humoral, cellular, and mucosal immune responses in mice. Challenge study showed that rPIV5-H5 prime-boost regimen provided sterile immunity against lethal clade 2.3.4.4b H5N1 virus infection in mice and ferrets. Notably, rPIV5-H5 prime-boost regimen provided protection in mice against challenge with lethal doses of heterologous clades 2.2, 2.3.2, and 2.3.4 H5N1, and clade 2.3.4.4h H5N6 viruses. These results revealed that rPIV5-H5 can elicit protective immunity against a diverse clade of highly pathogenic H5Ny virus infection in mammals, highlighting the potential of rPIV5-H5 as a pan-H5 influenza vaccine candidate for emergency use.IMPORTANCEClade 2.3.4.4b H5Ny highly pathogenic avian influenza viruses (HPAIVs) have been widely circulating in wild birds and domestic poultry all over the world, leading to infections in mammals, including humans. Here, we developed a recombinant PIV5-vectored vaccine candidate expressing the HA protein of clade 2.3.4.4b H5 virus. Intranasal immunization with rPIV5-H5 in mice induced airway mucosal IgA responses, high levels of antibodies, and robust T-cell responses. Importantly, rPIV5-H5 conferred complete protection in mice and ferrets against clade 2.3.4.4b H5N1 virus challenge, the protective immunity was extended against heterologous H5Ny viruses. Taken together, our data demonstrate that rPIV5-H5 is a promising vaccine candidate against diverse H5Ny influenza viruses in mammals.

Delivering COVID-19 vaccine trials at speed: the implementation of a phase IV UK multi-centre randomised controlled trial to determine safety and immunogenicity of COVID-19 vaccines co-administered with seasonal influenza vaccines (ComFluCOV).

BACKGROUND: In February 2021, the UK Department of Health and Social Care sought evidence on the safety and immunogenicity of COVID-19 and influenza vaccine co-administration to inform the 2021/2022 influenza vaccine policy. Co-administration could support vaccine uptake and reduce healthcare appointments. ComFluCOV was a randomised controlled trial designed to provide this evidence. This report outlines the methods used to deliver the trial in 6 months to answer an urgent public health question as part of the COVID-19 pandemic response. METHODS: ComFluCOV was commissioned by the Department of Health and Social Care and was managed by the Bristol Trials Centre, a UK-registered clinical trials unit. It was classed as an Urgent Public Health trial which facilitated fast-track regulatory approvals. Trial materials and databases were developed using in-house templates and those used in other COVID-19 vaccine trials. Participants were recruited by advertising, and via a trial website. Electronic trial systems enabled daily review of participant data. Weekly virtual meetings were held with stakeholders and trial sites. RESULTS: ComFluCOV was delivered within 6 months from inception to reporting, and trial milestones to inform the Department of Health and Social Care policy were met. Set-up was achieved within 1 month. Regulators provided expedited reviews, with feedback ahead of submission. Recruitment took place at 12 sites. Over 380 site staff were trained. Overall, 679 participants were recruited in two months. The final report to the Department of Health and Social Care was submitted in September 2021, following a preliminary safety report in May 2021. Trial results have been published. CONCLUSION: The rapid delivery of ComFluCOV was resource intensive. It was made possible in part due to a unique set of circumstances created by the pandemic situation including measures put in place to support urgent public health research and public support for COVID-19 vaccine research. Elements of the trial could be adopted to increase efficiency in 'non-pandemic' situations including working with a clinical trials unit to enable immediate mobilisation of a team of experienced researchers, greater sharing of resources between clinical trials units, use of electronic trial systems and virtual meetings. TRIAL REGISTRATION: ISRCTN14391248, submitted on 17/03/2021. Registered on 30/03/2021.

Downregulation of hypocretin/orexin after H1N1 Pandemrix vaccination of adolescent mice.

Narcolepsy type 1 (NT1), characterized by the loss of hypocretin/orexin (HCRT) production in the lateral hypothalamus, has been linked to Pandemrix vaccination during the 2009 H1N1 pandemic, especially in children and adolescents. It is still unknown why this vaccination increased the risk of developing NT1. This study investigated the effects of Pandemrix vaccination during adolescence on Hcrt mRNA expression in mice. Mice received a primary vaccination (50 µL i.m.) during prepubescence and a booster vaccination during peri-adolescence. Hcrt expression was measured at three-time points after the vaccinations. Control groups included both a saline group and an undisturbed group of mice. Hcrt expression was decreased after both Pandemrix and saline injections, but 21 days after the second injection, the saline group no longer showed decreased Hcrt expression, while the Pandemrix group still exhibited a significant reduction of about 60% compared to the undisturbed control group. This finding suggests that Pandemrix vaccination during adolescence influences Hcrt expression in mice into early adulthood. The Hcrt mRNA level did not reach the low levels known to induce NT1 symptoms, instead, our finding supports the multiple-hit hypothesis of NT1 that states that several insults to the HCRT system may be needed to induce NT1 and that Pandemrix could be one such insult.

Association of respiratory infections and the impact of vaccinations on cardiovascular diseases.

Influenza, pneumococcal, severe acute respiratory syndrome coronavirus 2, and respiratory syncytial virus infections are important causes of high morbidity and mortality in the elderly. Beyond the burden of infectious diseases, they are also associated with several non-infectious complications like cardiovascular events. A growing body of evidence in prospective studies and meta-analyses has shown the impact of influenza and pneumococcal vaccines on types of cardiovascular outcomes in the general population. Influenza vaccination showed a potential benefit for primary and secondary prevention of cardiovascular diseases across all ages. A reduced risk of cardiovascular events for individuals aged 65 years and older was associated with pneumococcal vaccination. Despite scientific evidence on the effectiveness, safety, and benefits of the vaccines and recommendations to vaccinate elderly patients and those with risk factors, vaccination rates remain sub-optimal in this population. Doubts about vaccine necessity or efficacy and concerns about possible adverse events in patients and physicians refer to delayed acceptance. Vaccination campaigns targeting increasing professional recommendations and public perceptions should be implemented in the coming years. The aim of this review paper is to summarize the effect of vaccination in the field of cardiovascular disease to achieve a higher vaccination rate in this patient population.

Immunogenicity and safety of concomitant bivalent COVID-19 and quadrivalent influenza vaccination: implications of immune imprinting and interference.

OBJECTIVES: Concomitant COVID-19 and influenza vaccination would be an efficient strategy. Although the co-administration of monovalent COVID-19 and influenza vaccinations showed acceptable immunogenicity, it remains unknown whether the bivalent COVID-19 vaccine could intensify immune interference. We aimed to evaluate the immunogenicity and safety of concomitant BA.5-based bivalent COVID-19 and influenza vaccination. METHODS: An open-label, nonrandomized clinical trial was conducted for 154 age-matched and sex-matched healthy adults between October 2022 and December 2022. Participants received either a concomitant bivalent COVID-19 mRNA booster and quadrivalent influenza vaccination (group C) or separate vaccinations (group S) at least 4 weeks apart. Solicited and unsolicited adverse events were reported up to 6 months postvaccination. Immunogenicity was evaluated by anti-spike (S) IgG electrochemiluminescence immunoassay, focus reduction neutralization test, and hemagglutination inhibition assay. RESULTS: Group C did not meet the noninferiority criteria for the seroconversion rates of anti-S IgG and neutralizing antibodies against the wild-type SARS-CoV-2 strain compared with group S (44.2% vs. 46.8%, difference of -2.6% [95% CI, -18 to 13.4]; 44.2% vs. 57.1%, difference of -13.0% [95% CI to -28.9 to 2.9]). However, group C showed a stronger postvaccination neutralizing antibody response against Omicron BA.5 (72.7% vs. 64.9%). Postvaccination geometric mean titers for SARS-CoV-2 and influenza strains were similar between groups, except for influenza B/Victoria. Most adverse events were mild and comparable between the study groups. DISCUSSION: Concomitant administration of bivalent COVID-19 mRNA and quadrivalent influenza vaccines showed tolerable safety profiles and sufficient immunogenicity, particularly attenuating immune imprinting induced by previous ancestral vaccine strains.

Influvac Tetra: clinical experience on safety, efficacy, and immunogenicity.

INTRODUCTION: This paper summarizes the safety and immunogenicity data of Influvac Tetra across all age groups starting from 6 months of age, obtained during its clinical development program. AREAS COVERED: The article covers the clinical development program of Influvac Tetra based on five registration studies that included different age groups, different comparators, and participants from Europe and Asia. Safety and immunogenicity were assessed in all studies and in one study, the efficacy of Influvac Tetra was assessed. EXPERT OPINION: Seasonal influenza is a vaccine-preventable disease that can cause serious complications. Several types of influenza vaccines are available, including egg-based (standard dose, high dose, and adjuvanted), cell-based, and recombinant. The COVID-19 pandemic has stimulated innovation in the development such as mRNA vaccines. However, these vaccines are still in development and the true value still has to be proven. Regardless of the type of vaccine, it is also important to increase overall vaccination coverage. ECDC recommends that EU Member States implement action plans and policies aimed at reaching 75% coverage in at-risk groups and healthcare workers. Even so, vaccine coverage is still far from recommended.

Global burden of vaccine-associated anaphylaxis and their related vaccines, 1967-2023: A comprehensive analysis of the international pharmacovigilance database.

BACKGROUND: Vaccine-associated anaphylaxis is a rare but life-threatening reaction that occurs within minutes to hours of exposure to allergens. As studies utilizing large-scale data to investigate this topic are limited, further research is needed to assess its burden, long-term trends, and associated risk factors so as to gain a comprehensive understanding of vaccine-associated anaphylaxis globally. Therefore, this study aimed to investigate the global burden of vaccine-associated anaphylaxis and related vaccines. METHOD: This study utilized the World Health Organization International Pharmacovigilance Database, in which reports of vaccine-associated anaphylaxis between 1967 and 2023 were obtained (total reports = 131,255,418). We estimated the global reporting counts, reported odds ratio (ROR), and information component (IC) to identify the relationship between 19 vaccines and associated anaphylaxis in 156 countries and territories. RESULTS: We identified 31,676 reports of vaccine-associated anaphylaxis among 363,290 reports of all-cause anaphylaxis. The cumulative number of reports on vaccine-associated anaphylaxis has gradually increased over time, with a dramatic increase after 2020, owing to reports of COVID-19 mRNA vaccine-associated anaphylaxis. The typhoid vaccines were associated with the most anaphylactic reports (ROR: 4.35; IC0.25 : 1.86), followed by encephalitis (3.27; 1.45), hepatitis B (2.69; 1.30), cholera (2.65; 0.54), hepatitis A (2.44; 1.12), influenza (2.36; 1.16), inactivated whole-virus COVID-19 (2.21; 1.02), and COVID-19 mRNA vaccines (1.89; 0.79). In terms of age- and sex-specific risks, vaccine-associated anaphylaxis reports develop more frequently in females and at young ages. The Ad5-vectored COVID-19 vaccine anaphylaxis reports were associated with the highest fatality rate (15.0%). CONCLUSIONS: Although multiple vaccines are associated with various spectra and risks of anaphylaxis, clinicians should recognize the possibility of anaphylaxis occurring with all vaccines, particularly the COVID-19 mRNA and inactivated whole-virus COVID-19 vaccines, and consider the risk factors associated with vaccine anaphylaxis reports. Further studies are warranted to identify better ways of preventing vaccine-associated anaphylaxis.

[Efficacy and safety of pediatric flu vaccination: a systematic review]. / Eficacia y seguridad de la vacunación antigripal pediátrica: una revisión sistemática.

OBJECTIVE: Children are at a higher risk of influenza infection compared to the general population. The World Organization Health and recommendations of the Vaccine Advisory Committee of the Spanish Association of Pediatrics contemplate annual vaccination as the most effective way to prevent the disease. Therefore, the purpose of this review was to update information on efficacy and safety in the anti -shed vaccine in children and adolescents. METHODS: A search in four electronic databases (Scopus, Cumulative Index to Nursing and Allied Health Literature, Medline / Pubmed, Google Scholar and Cochrane), as well as a manual search to identify original research published between 2012 and 2022. The guidelines of ANALYSIS (PRISMACR) as a preferred report element for systematic reviews. RESULTS: Seven original research articles were included where two issues of antigripal vaccination were identified in healthy children/adolescents and with pathologies. The efficacy (between approximately 30% and 80%) varied depending on the vaccine used and circulating subtypes. Most adverse reactions were mild intensity, and the most common local adverse event was pain in the injection site. CONCLUSIONS: We positively highlight the safety of pediatric flu vaccination in analyzed studies, on the contrary, with respect to the efficacy of flu vaccination, we observe a wide variability of results. There is a clear need to continue conducting efficacy and safety studies in the child.