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.

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.

Safety and Immunogenicity of Bivalent RSVpreF Vaccine Coadministered With Seasonal Inactivated Influenza Vaccine in Older Adults

BACKGROUND

Respiratory syncytial virus (RSV) and influenza are both typically seasonal diseases, with winter peaks in temperate climates. Coadministration of an RSV vaccine and influenza vaccine could be a benefit, requiring 1 rather than 2 visits to a healthcare provider for individuals receiving both vaccines.

METHODS

The primary immunogenicity objective of this phase 3, 1:1 randomized, double-blind, placebo-controlled study in healthy adults aged ≥65 years in Australia was to demonstrate noninferiority of immune responses with coadministration of the stabilized RSV prefusion F protein-based vaccine (RSVpreF) and seasonal inactivated influenza vaccine (SIIV) versus SIIV or RSVpreF administered alone, using a 1.5-fold noninferiority margin (lower bound 95% confidence interval >.667). Safety and tolerability were evaluated by collecting reactogenicity and adverse event data.

RESULTS

Of 1403 participants randomized, 1399 received vaccinations (median age, 70; range, 65‒91 years). Local reactions and systemic events were mostly mild or moderate when RSVpreF was coadministered with SIIV or administered alone. No vaccine-related serious adverse events were reported. Geometric mean ratios were 0.86 for RSV-A and 0.85 for RSV-B neutralizing titers at 1 month after RSVpreF administration and 0.77 to 0.90 for strain-specific hemagglutination inhibition assay titers at 1 month after SIIV. All comparisons achieved the prespecified 1.5-fold noninferiority margin.

CONCLUSIONS

The primary study objectives were met, demonstrating noninferiority of RSVpreF and SIIV immune responses when RSVpreF was coadministered with SIIV and that RSVpreF had an acceptable safety and tolerability profile when coadministered with SIIV. The results of this study support coadministration of RSVpreF and SIIV in an older-adult population.

CLINICAL TRIALS REGISTRATION

https://clinicaltrials.gov/study/NCT05301322.

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.

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.

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 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.

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.

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).

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.

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.

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.

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.

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]

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.

Immunogenicity and safety of vaccines in multiple sclerosis: A systematic review and meta-analysis

BACKGROUND

Seroconversion rate of vaccines varies and requires further elucidation in patients with multiple sclerosis (MS) under treatment with disease-modifying therapies (DMTs). We aimed to investigate this in a systematic review and meta-analysis.

METHODS

MEDLINE(PubMed) and Cochrane databases were searched based on a pre-specified protocol (PROSPERO: CRD42020202018). Studies reporting on patients with MS, diagnosed with McDonald criteria getting vaccinated with any type of vaccine were included in the analysis. The primary endpoint was the incidence of patients being seropositive and experience adverse events after vaccination. Outcomes were expressed as proportions with respective 95% confidence interval (CI). Two reviewers independently screened and reviewed existing literature and assessed study quality with the Methodological index for non-randomized studies.

RESULTS

Of 295 articles, 45 studies were analyzed. Seroconversion after COVID-19 vaccines was 76% (95% CI, 70-80; I2 = 95%; 20 studies including 5601 patients. Protection was lower in patients treated with anti-CD20 antibodies and sphingosine-1-phosphate receptor (S1PR) modulators compared to untreated patients or treatment with other DMTs. Relapse occurred in 2% (95% CI, 1-3; I2 = 86%; 16 studies including 7235 patients). Seroconversion after seasonal influenza vaccines was 82% (95% CI, 65-91; I2 = 90%; 6 studies including 490 patients). Relapse rate was similar to this after COVID-19 vaccination.

CONCLUSION

The majority of MS patients vaccinated for COVID-19 or seasonal influenza mount an adequate immune response without safety concerns. Data on other vaccines are limited.

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.

Pediatric hemophagocytic lymphohistiocytosis after concomitant administration of SARS-CoV-2 vaccine and influenza vaccine

Hemophagocytic lymphohistiocytosis (HLH) is a highly lethal disease characterized by fever, cytopenia, splenomegaly, and hemophagocytosis. Whereas infectious diseases, malignant tumors, and autoimmune diseases are often triggers for HLH, reports of HLH associated with vaccination are limited. In this report, we describe a case of HLH in a 12-year-old female patient after simultaneous administration of the bivalent messenger RNA severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine and quadrivalent inactivated influenza vaccine. The patient presented to our hospital with fever on the day after vaccination. Considering the splenomegaly, cytopenia, hemophagocytosis in the bone marrow, and high ferritin level, HLH was diagnosed 12 days after vaccination. Various tests ruled out any infectious disease, malignant tumor, or autoimmune disease. The patient was treated only with 2 mg/kg/day of oral prednisolone, fever improved 13 days after vaccination, and blood test findings rapidly improved. Although HLH after SARS-CoV-2 vaccination or concomitant administration with influenza vaccination is still rare, we emphasize the importance of early HLH diagnosis when persistent fever is observed following vaccination.

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.

Real world evidence for public health decision-making on vaccination policies: perspectives from an expert roundtable

INTRODUCTION

Influenza causes significant morbidity and mortality, but influenza vaccine uptake remains below most countries' targets. Vaccine policy recommendations vary, as do procedures for reviewing and appraising the evidence.

AREAS COVERED

During a series of roundtable discussions, we reviewed procedures and methodologies used by health ministries in four European countries to inform vaccine recommendations. We review the type of evidence currently recommended by each health ministry and the range of approaches toward considering randomized controlled trials (RCTs) and real-world evidence (RWE) studies when setting influenza vaccine recommendations.

EXPERT OPINION

Influenza vaccine recommendations should be based on data from both RCTs and RWE studies of efficacy, effectiveness, and safety. Such data should be considered alongside health-economic, cost-effectiveness, and budgetary factors. Although RCT data are more robust and less prone to bias, well-designed RWE studies permit timely evaluation of vaccine benefits, effectiveness comparisons over multiple seasons in large populations, and detection of rare adverse events, under real-world conditions. Given the variability of vaccine effectiveness due to influenza virus mutations and increasing diversification of influenza vaccines, we argue that consideration of both RWE and RCT evidence is the best approach to more nuanced and timely updates of influenza vaccine recommendations.

Interstitial lung disease following COVID-19 vaccination: a disproportionality analysis using the Global Scale Pharmacovigilance Database (VigiBase)

BACKGROUND AND OBJECTIVE

Despite several case reports, population-based studies on interstitial lung disease (ILD) following COVID-19 vaccination are lacking. Given the unprecedented safety issue of COVID-19 vaccination, it is important to assess the worldwide patterns of ILD following COVID-19 vaccination. This study aimed to investigate the signals of COVID-19 vaccine-associated ILD compared with other vaccinations using disproportionality analysis.

METHODS

We analysed the VigiBase database during the period between 13 December 2020 and 26 January 2023. We adopted the case/non-case approach to assess the disproportionality signal of ILD for COVID-19 vaccines via 1:10 matching by age and sex. We compared COVID-19 vaccines with all other vaccines as the reference group.

RESULTS

Among 1 233 969 vaccine-related reports, 679 were reported for ILD. The majority of ILD cases were related to tozinameran (376 reports, 55.4%), Vaxzevria (129 reports, 19.0%) and elasomeran (78 reports, 11.5%). The reporting OR of ILD following COVID-19 vaccination was 0.86 (95% CI 0.64 to 1.15) compared with all other vaccines.

CONCLUSION

No significant signal of disproportionate reporting of ILD was observed for COVID-19 vaccines compared with all other vaccines. Moreover, when compared with the influenza vaccines that are known to cause ILD, no signal was observed. This study results might help decision-making on the subsequent COVID-19 vaccination strategy of ILD. Further large and prospective studies are required for more conclusive evidence.

Immunogenicity, safety, and preliminary efficacy evaluation of OVX836, a nucleoprotein-based universal influenza A vaccine candidate: a randomised, double-blind, placebo-controlled, phase 2a trial

BACKGROUND

OVX836, a recombinant vaccine containing the nucleoprotein of the influenza A virus A/WSN/1933 (H1N1) and the oligomerisation domain OVX313, has displayed a good safety profile and elicited dose-dependent humoral and cellular immune responses at 90 μg or 180 μg (intramuscularly) in previous clinical trials. The aim of this study was to explore higher doses, since no maximum tolerated dose had been reached.

METHODS

In this phase 2a, randomised, double-blind, placebo-controlled study, we recruited 137 healthy adults aged 18-55 years in a single centre in Belgium. Participants were randomly assigned (interactive web response system; block size=4) using SAS (version 9.4) to receive one single intramuscular administration of OVX836 influenza vaccine at three doses (180 μg [n=33], 300 μg [n=35], and 480 μg [n=36]) or placebo (n=33). The two primary endpoints were the safety and the cell-mediated immune response to OVX836 at the three doses in terms of change of nucleoprotein-specific IFNγ spot forming cell (SFC) frequencies in the peripheral blood mononuclear cell (PBMC) population, measured by IFNγ ELISpot, at day 8 versus pre-injection baseline (day 1). The population used for the safety analysis is the modified intention-to-treat cohort. The population used for the immunogenicity analysis is the per-protocol cohort. This trial is registered with ClinicalTrials.gov, NCT05060887, and EudraCT, 2021-002535-39.

FINDINGS

Participants were recruited between Nov 15, 2021, and Feb 1, 2022. OVX836 had a favourable safety profile up to 480 μg without reaching the maximum tolerated dose, and showed a good safety profile at all doses with mild local and systemic reactogenicity. 7 days after vaccination, although no significant differences were observed between the doses, OVX836 increased the frequency of nucleoprotein-specific IFNγ SFCs per million PBMCs from days 1 to 8 (primary endpoint): by 124 SFCs per 106 PMBCs (95% CI 67 to 180; p=0·002) at 180 μg; by 202 SFCs per 106 PMBCs (95% CI 138 to 267; p<0·0001) at 300 μg; by 223 SFCs per 106 PMBCs (95% CI 147 to 299; p<0·0001) at 480 μg; and decreased by 1 SFCs per 106 PMBCs (95% CI -24 to 22] in the placebo group (Kruskal-Wallis test p<0·0001 followed by Mann-Whitney's tests; per-protocol cohort). Dose-dependent and polyfunctional nucleoprotein-specific CD4 T-cell responses were observed, and CD8 T-cell responses were elicited at 300 μg and 480 μg (secondary endpoints).

INTERPRETATION

OVX836 appears to be a safe and well tolerated candidate vaccine that elicits humoral and cellular nucleoprotein-specific immune responses (including CD8 T cells at the highest dose levels) and showed a preliminary signal of protection against influenza. Therefore, OVX836 is a promising vaccine candidate for universal influenza A prevention, that warrants further trials.

FUNDING

OSIVAX, Bpifrance, Wallonia Region, and the EUs Horizon 2020 Research and Innovation Program.

Sex differences in adverse events following seasonal influenza vaccines: a meta-analysis of randomised controlled trials

BACKGROUND

Despite being a vaccine-preventable disease, influenza remains a major public health threat with vaccine safety concerns reducing vaccine acceptability. Immune responses to vaccines and adverse events may differ between males and females, but most studies do not report results by sex. Using data from clinical trials, we explored sex differences in adverse events following seasonal influenza vaccines.

METHODS

We obtained data for phase III randomised controlled trials identified through a systematic review and clinical trials registries, and performed a two-stage meta-analysis. Risk ratios (RR) and 95% confidence intervals (95% CI) comparing solicited reactions in females versus males were pooled using the Mantel-Haenszel method and a random-effects model. We used the ROBINS-I tool to assess risk of bias and the I2 statistic for heterogeneity. Main analysis was stratified by age: 18-64 years and ≥65 years.

RESULTS

The dataset for this analysis included 34 343 adults from 18 studies (12 with individual-level data and 6 with aggregate data). There was a higher risk of injection site reactions in females compared with males for both younger and older participants, with RRs of 1.29 (95% CI 1.21 to 1.37) and 1.43 (95% CI 1.28 to 1.60), respectively. Higher risk in females was also observed for systemic reactions, with RRs of 1.25 (95% CI 1.20 to 1.31) and 1.27 (95% CI 1.20 to 1.34) for younger and older participants, respectively. We also observed elevated risks of severe reactions in females, with a higher RR in younger versus older participants for systemic reactions (RRs 2.12 and 1.48, p=0.03, I2=79.7%). RRs were not found to vary between quadrivalent and trivalent vaccines.

CONCLUSION

This meta-analysis suggested a higher risk of solicited reactions following influenza vaccines for females compared with males, irrespective of age and vaccine type. Transparent communication of this risk could increase the trust in vaccines and limit vaccine hesitancy. Future studies should report results stratified by sex and explore the role of gender in the occurrence of adverse events.

The Effect of Sex on the Incidence, Latency, Duration and Perceived Burden of Adverse Events Following Seasonal Influenza Vaccination in the Netherlands

INTRODUCTION

The annual reformulation of the seasonal influenza vaccine results in fluctuating frequencies and severity of adverse effects following immunization (AEFIs), which stresses the importance of pharmacovigilance. Also, sex-related factors are known to influence the development of AEFIs. This study aims to describe the difference in incidence and course (i.e., time-to-onset, time-to-recovery, and perceived burden) of AEFIs between males and females after seasonal influenza vaccination.

METHODS

We assessed data from cohort event monitoring studies, which were performed over nine consecutive years (2013-2021), each covering several months during the seasonal influenza campaign in the Netherlands. Participants reported information about AEFIs over a 30-day period in three questionnaires. The effect of sex, age, body mass index, study year, and comorbidities on the incidence of any AEFI, local reactions, fever and the five most reported AEFIs was analyzed using logistic regression. The difference in time-to-onset, time-to-recovery, and perceived burden between males and females was analyzed by the Kruskal-Wallis test.

RESULTS

The cohort included 7789 participants (53.0% females). Females had around 2.5-fold (p < 0.001) higher odds of developing any AEFI compared with males. Some study years and comorbidities were positively associated with AEFI incidence, whereas age was negatively associated. An AEFI had a significant shorter time-to-onset, a longer time-to-recovery, and a higher perceived burden in females compared to males.

CONCLUSION

Overall, the results confirm that females experience AEFIs more often than males. Additionally, this study shows that the course of AEFIs only partially differs between the sexes.

Safety and immunogenicity of influenza A(H3N2) component vaccine in juvenile systemic lupus erythematosus

INTRODUCTION

Seasonal influenza A (H3N2) virus is an important cause of morbidity and mortality in the last 50 years in population that is greater than the impact of H1N1. Data assessing immunogenicity and safety of this virus component in juvenile systemic lupus erythematosus (JSLE) is lacking in the literature.

OBJECTIVE

To evaluate short-term immunogenicity and safety of influenza A/Singapore (H3N2) vaccine in JSLE.

METHODS

24 consecutive JSLE patients and 29 healthy controls (HC) were vaccinated with influenza A/Singapore/INFIMH-16-0019/2016(H3N2)-like virus. Influenza A (H3N2) seroprotection (SP), seroconversion (SC), geometric mean titers (GMT), factor increase in GMT (FI-GMT) titers were assessed before and 4 weeks post-vaccination. Disease activity, therapies and adverse events (AE) were also evaluated.

RESULTS

JSLE patients and controls were comparable in current age [14.5 (10.1-18.3) vs. 14 (9-18.4) years, p = 0.448] and female sex [21 (87.5%) vs. 19 (65.5%), p = 0.108]. Before vaccination, JSLE and HC had comparable SP rates [22 (91.7%) vs. 25 (86.2%), p = 0.678] and GMT titers [102.3 (95% CI 75.0-139.4) vs. 109.6 (95% CI 68.2-176.2), p = 0.231]. At D30, JSLE and HC had similar immune response, since no differences were observed in SP [24 (100%) vs. 28 (96.6%), p = 1.000)], SC [4 (16.7%) vs. 9 (31.0%), p = 0.338), GMT [162.3 (132.9-198.3) vs. 208.1 (150.5-287.8), p = 0.143] and factor increase in GMT [1.6 (1.2-2.1) vs. 1.9 (1.4-2.5), p = 0.574]. SLEDAI-2K scores [2 (0-17) vs. 2 (0-17), p = 0.765] and therapies remained stable throughout the study. Further analysis of possible factors influencing vaccine immune response among JSLE patients demonstrated similar GMT between patients with SLEDAI < 4 compared to SLEDAI ≥ 4 (p = 0.713), as well as between patients with and without current use of prednisone (p = 0.420), azathioprine (p = 1.0), mycophenolate mofetil (p = 0.185), and methotrexate (p = 0.095). No serious AE were reported in both groups and most of them were asymptomatic (58.3% vs. 44.8%, p = 0.958). Local and systemic AE were alike in both groups (p > 0.05).

CONCLUSION

This is the first study that identified adequate immune protection against H3N2-influenza strain with additional vaccine-induced increment of immune response and an adequate safety profile in JSLE. ( www.

CLINICALTRIALS

gov , NCT03540823).

Influenza vaccination coverage among persons ages six months and older in the Vaccine Safety Datalink in the 2017-18 through 2022-23 influenza seasons

BACKGROUND

In the United States, annual vaccination against seasonal influenza is recommended for all people ages ≥ 6 months. Vaccination coverage assessments can identify populations less protected from influenza morbidity and mortality and help to tailor vaccination efforts. Within the Vaccine Safety Datalink population ages ≥ 6 months, we report influenza vaccination coverage for the 2017-18 through 2022-23 seasons.

METHODS

Across eight health systems, we identified influenza vaccines administered from August 1 through March 31 for each season using electronic health records linked to immunization registries. Crude vaccination coverage was described for each season, overall and by self-reported sex; age group; self-reported race and ethnicity; and number of separate categories of diagnoses associated with increased risk of severe illness and complications from influenza (hereafter referred to as high-risk conditions). High-risk conditions were assessed using ICD-10-CM diagnosis codes assigned in the year preceding each influenza season.

RESULTS

Among individual cohorts of more than 12 million individuals each season, overall influenza vaccination coverage increased from 41.9 % in the 2017-18 season to a peak of 46.2 % in 2019-20, prior to declaration of the COVID-19 pandemic. Coverage declined over the next three seasons, coincident with widespread SARS-CoV-2 circulation, to a low of 40.3 % in the 2022-23 season. In each of the six seasons, coverage was lowest among males, 18-49-year-olds, non-Hispanic Black people, and those with no high-risk conditions. While decreases in coverage were present in all age groups, the declines were most substantial among children: 2022-23 season coverage for children ages six months through 8 years and 9-17 years was 24.5 % and 22.4 % (14 and 10 absolute percentage points), respectively, less than peak coverage achieved in the 2019-20 season.

CONCLUSIONS

Crude influenza vaccination coverage increased from 2017 to 18 through 2019-20, then decreased to the lowest level in the 2022-23 season. In this insured population, we identified persistent disparities in influenza vaccination coverage by sex, age, and race and ethnicity. The overall low coverage, disparities in coverage, and recent decreases in coverage are significant public health concerns.

Immunogenicity and safety of influenza vaccine in patients with lung cancer receiving immune checkpoint inhibitors: A single-center prospective cohort study

INTRODUCTION

Patients with lung cancer have a high risk of influenza complications. International guidelines recommend annual influenza vaccination for patients with cancer. Immune checkpoint inhibitors (ICIs) are progressively used to treat lung cancer. Data regarding immunogenicity and safety of influenza vaccine are limited in patients with lung cancer receiving ICIs; therefore, we conducted this single-center, prospective observational study in the Japanese population.

METHODS

Patients with lung cancer receiving ICIs and influenza immunization were enrolled. Blood samples were collected from patients for serum antibody titer measurement pre- and 4 ± 1 weeks post-vaccination. The primary endpoint was seroprotection rate (sP) at 4 ± 1 weeks post-vaccination. The secondary endpoints were geometric mean titer (GMT), mean fold rise, seroresponse rate (sR), seroconversion rate (sC), and immune-related adverse events (irAEs), defined as adverse effects caused by ICI administration, 6 months post-vaccination.

RESULTS

Influenza vaccination in the 23 patients included in the immunogenicity analyses significantly increased GMT for all strains, and sP, sR, and sC were 52%-91%, 26%-39%, and 26%-35%, respectively. In the 24 patients included in the safety analyses, 7 (29%) and 5 (21%) patients exhibited systemic and local reactions, respectively. Only one patient (4%) (hypothyroidism, grade 2) showed post-vaccination irAEs.

CONCLUSIONS

Overall, influenza vaccination in patients with lung cancer receiving ICIs showed acceptable immunogenicity and safety, thus supporting annual influenza vaccination in this population.

The role of vaccination in COPD: influenza, SARS-CoV-2, pneumococcus, pertussis, RSV and varicella zoster virus

Exacerbations of COPD are associated with worsening of the airflow obstruction, hospitalisation, reduced quality of life, disease progression and death. At least 70% of COPD exacerbations are infectious in origin, with respiratory viruses identified in approximately 30% of cases. Despite long-standing recommendations to vaccinate patients with COPD, vaccination rates remain suboptimal in this population.Streptococcus pneumoniae is one of the leading morbidity and mortality causes of lower respiratory tract infections. The Food and Drug Administration recently approved pneumococcal conjugate vaccines that showed strong immunogenicity against all 20 included serotypes. Influenza is the second most common virus linked to severe acute exacerbations of COPD. The variable vaccine efficacy across virus subtypes and the impaired immune response are significant drawbacks in the influenza vaccination strategy. High-dose and adjuvant vaccines are new approaches to tackle these problems. Respiratory syncytial virus is another virus known to cause acute exacerbations of COPD. The vaccine candidate RSVPreF3 is the first authorised for the prevention of RSV in adults ≥60 years and might help to reduce acute exacerbations of COPD. The 2023 Global Initiative for Chronic Lung Disease report recommends zoster vaccination to protect against shingles for people with COPD over 50 years.

Developmental and reproductive safety of Advax-CpG55.2™ adjuvanted COVID-19 and influenza vaccines in mice

SpikoGen® is a recombinant spike protein vaccine against COVID-19 that obtained marketing authorization in the Middle East on October 6th, 2021, becoming the first adjuvanted protein-based COVID-19 vaccine of its type to achieve approval. SpikoGen® vaccine utilizes a unique adjuvant Advax-CpG55.2, which comprises delta inulin and CpG55.2 oligonucleotide, a synthetic human toll-like receptor (TLR)-9 agonist. As part of a safety assessment, developmental and reproductive toxicity (DART) studies were undertaken in mice of Advax-CpG55.2 adjuvanted formulations including SpikoGen®, a H7 hemagglutinin influenza vaccine (rH7HA), the bivalent combination of SpikoGen® and rH7HA, and a next-generation quadrivalent spike protein vaccine. In the first study, vaccines were administered intramuscularly to pregnant dams on gestation days (GD) 6.5 and 12.5, and in the second two doses were given in the pre-mating period with a further two doses during gestation. The doses used in the pregnant mice were 250-1000 times the usual human doses on a weight for weight basis. Strong serum antibody responses with neutralizing activity against the relevant virus were seen in the immunized dams and also at the time of weaning in the sera of their pups, consistent with robust maternal antibody transfer. No adverse effects of any of the vaccine formulations were observed in the immunized dams or their pups. Notably, there were no adverse effects of any of the Advax-CpG55.2 adjuvanted vaccines on female mating performance, fertility, ovarian or uterine parameters, embryo-fetal or postnatal survival, fetal growth, or neurofunctional development. No evidence of antigen interference was observed when SpikoGen® vaccine was mixed and co-administered with influenza hemagglutinin vaccine to pregnant dams. Together with the strong safety profile of SpikoGen® vaccine seen in adults and children in human trials, this DART study data supports the safety of Advax-CpG55.2 adjuvanted COVID-19 and influenza vaccine in women of childbearing potential including during pregnancy.

Simultaneous administration of mRNA COVID-19 bivalent booster and influenza vaccines

The U.S. Food and Drug Administration authorized use of mRNA COVID-19 bivalent booster vaccines on August 31, 2022. Currently, CDC's clinical guidance states that COVID-19 and other vaccines may be administered simultaneously. At time of authorization and recommendations, limited data existed describing simultaneous administration of COVID-19 bivalent booster and other vaccines. We describe simultaneous influenza and mRNA COVID-19 bivalent booster vaccine administration between August 31-December 31, 2022, among persons aged ≥6 months in the Vaccine Safety Datalink (VSD) by COVID-19 bivalent booster vaccine type, influenza vaccine type, age group, sex, and race and ethnicity. Of 2,301,876 persons who received a COVID-19 bivalent booster vaccine, 737,992 (32.1%) received simultaneous influenza vaccine, majority were female (53.1%), aged ≥18 years (91.4%), and non-Hispanic White (55.7%). These findings can inform future VSD studies on simultaneous influenza and COVID-19 bivalent booster vaccine safety and coverage, which may have implications for immunization service delivery.

Immunogenicity and Reactogenicity of Coadministration of COVID-19 and Influenza Vaccines

Importance

COVID-19 and seasonal influenza vaccines were previously given separately, although their coadministration is warranted for vaccination adherence. Limited data on their coadministration have been published.

Objective

To compare the reactogenicity and immunogenicity of COVID-19 and influenza vaccinations administered together with those of COVID-19 vaccination alone.

Design, Setting, and Participants

This prospective cohort study included health care workers at a large tertiary medical center in Israel who received the Influvac Tetra (Abbott) influenza vaccine (2022/2023), the Omicron BA.4/BA.5-adapted bivalent (Pfizer/BioNTech) vaccine, or both. Vaccination began in September 2022, and data were collected until January 2023. Vaccines were offered to all employees and were coadministered or given separately. Adverse reaction questionnaires were sent, and serologic samples were also collected.

Exposures

Receiving COVID-19 vaccine, influenza vaccine, or both.

Main Outcomes and Measures

The main outcomes for the reactogenicity analysis were symptoms following vaccine receipt, assessed by a digital questionnaire: any local symptoms; fever; weakness or fatigue; any systemic symptoms; and their duration. The immunogenicity analysis' outcome was postvaccination anti-spike IgG titer.

Results

This study included 2 cohorts for 2 separate analyses. The reactogenicity analysis included 588 participants (of 649 questionnaire responders): 85 in the COVID-19 vaccine-alone group (median [IQR] age, 71 [58-74] years; 56 [66%] female); 357 in the influenza vaccine-alone group (median [IQR] age, 55 [40-65] years; 282 [79%] female); and 146 in the coadministration group (median [IQR] age, 61 [50-71] years; 81 [55%] female). The immunogenicity analysis included 151 participants: 74 participants in the COVID-19 vaccine group (median [IQR] age, 67 [56-73] years; 45 [61%] female) and 77 participants in the coadministration group (median [IQR] age, 60 [49-73] years; 42 [55%] female). Compared with COVID-19 vaccination alone, the risk of systemic symptoms was similar in the coadministration group (odds ratio, 0.82; 95% CI, 0.43-1.56). Geometric mean titers in the coadministration group were estimated to be 0.84 (95% CI, 0.69-1.04) times lower than in the COVID-19 vaccine-alone group.

Conclusions and Relevance

In this cohort study of health care workers who received a COVID-19 vaccine, an influenza vaccine, or both, coadministration was not associated with substantially inferior immune response or to more frequent adverse events compared with COVID-19 vaccine administration alone, supporting the coadministration of these vaccines.

Risk of Miscarriage in Relation to Seasonal Influenza Vaccination Before or During Pregnancy

OBJECTIVE

To evaluate the association between seasonal influenza vaccination and miscarriage using data from an ongoing, prospective cohort study.

METHODS

We analyzed 2013-2022 data from PRESTO (Pregnancy Study Online), a prospective prepregnancy cohort study of female pregnancy planners and their male partners in the United States and Canada. Female participants completed a baseline questionnaire and then follow-up questionnaires every 8 weeks until pregnancy, during early and late pregnancy, and during the postpartum period. Vaccine information was self-reported on all questionnaires. Miscarriage was identified from self-reported information during follow-up. Male partners were invited to complete a baseline questionnaire only. We used Cox proportional hazard models to estimate the hazard ratio (HR) and 95% CI for the association between vaccination less than 3 months before pregnancy detection through the 19th week of pregnancy and miscarriage, with gestational weeks as the time scale. We modeled vaccination as a time-varying exposure and used propensity-score fine stratification to control for confounding from seasonal and female partner factors.

RESULTS

Of 6,946 pregnancies, 23.3% of female partners reported exposure to influenza vaccine before or during pregnancy: 3.2% during pregnancy (gestational age 4-19 weeks) and 20.1% during the 3 months before pregnancy detection. The miscarriage rate was 16.2% in unvaccinated and 17.0% among vaccinated participants. Compared with no vaccine exposure, influenza vaccination was not associated with increased rate of miscarriage when administered before (HR 0.99, 95% CI 0.81-1.20) or during (HR 0.83, 95% CI 0.47-1.47) pregnancy. Of the 1,135 couples with male partner vaccination data available, 10.8% reported vaccination less than 3 months before pregnancy. The HR for the association between male partner vaccination and miscarriage was 1.17 (95% CI 0.73-1.90).

CONCLUSION

Influenza vaccination before or during pregnancy was not associated with miscarriage.

Influenza vaccine uptake and associated factors in adult patients with type 2 diabetes in a general outpatient clinic in Hong Kong

BACKGROUND AND OBJECTIVES

This study examined the uptake of influenza vaccine (Vaxigrip Tetra, Sanofi-Aventis) among local patients with type 2 diabetes (T2D) and their intention to receive future flu vaccines. We also explored associations between factors pertinent to the Health Belief Model (HBM) and vaccination behaviour. Based on these findings, targeted strategies to improve flu vaccine uptake are proposed.

METHOD

In all, 499 patients with diabetes were recruited from a government general outpatient clinic (GOPC) in Hong Kong between 1 and 14 March 2021. A cross-sectional, questionnaire-based study to investigate vaccination behaviours and the HBM was conducted. A self-reported questionnaire that included sociodemographic data of participants' and patients' knowledge and perceptions related to flu vaccines based on the HBM framework was used. Study subjects aged <18 years and those who were unable to provide consent or had contraindications to flu vaccine were excluded from the study.

RESULTS

Among the study sample, the reported flu vaccine uptake rate was 42% during 2020. Results from multivariate logistic analyses revealed a positive correlation between the likelihood of vaccination and factors pertinent to the HBM, such as knowledge that flu vaccine is required annually, not considering side effects from flu vaccine uptake and having better access to flu vaccine.

DISCUSSION

The rate of flu vaccine uptake in our study population was suboptimal. Given the significance of influenza among patients with T2D, various public health interventions should be used to promote annual flu vaccine uptake.

Safety profile and SARS-CoV-2 breakthrough infections among HCWs receiving anti-SARS-CoV-2 and influenza vaccines simultaneously: an Italian observational study

In October/December 2021, World Health Organization and other international agencies recommended the offer of the third dose of anti-SARS-CoV-2 vaccine. In this period, the routine offer of seasonal influenza vaccination was also guaranteed and simultaneous administration of the two vaccines was encouraged. This study aims to evaluate the safety profile and to estimate the incidence of SARS-CoV-2 breakthrough infections in subjects receiving the anti-SARS-CoV-2 and influenza vaccines simultaneously. The study population was represented by healthcare workers (HCWs) of Bari Policlinico General Hospital who received the influenza (Flucelvax Tetra®) and/or anti-SARS-CoV-2 vaccination (BNT162b2 mRNA COVID-19 vaccine, Comirnaty®) either in coadministration or separately in October 2021. Reports of adverse events following immunization (AEFIs) were investigated to study the safety of both vaccines in coadministration and in separate-instance administration. Post-vaccination SARS-CoV-2 breakthrough infection was also studied. 942 HCWs accepted to join our study. 610/942 received both vaccines simultaneously. 25.26 % subjects (238/942) were only vaccinated against SARS-CoV-2, while the remaining 94 HCWs received the influenza vaccination first and subsequently received the anti-SARS-CoV2 booster dose. 717 HCWs reported AEFIs (Reporting Rate 76.1 per 100 subjects). Simultaneous administration of the two vaccines was not related with an increase of the rate of AEFIs compared to the single administration of SARS-CoV-2 vaccine, but the AEFIs' rate was lower among subjects who received only influenza vaccine. Post-vaccination SARS-CoV-2 infections were notified for 41.5 % of enrolled subjects (391/942). Incidence of breakthrough infection and symptomatic disease was not significantly different between the simultaneous administration group and other subjects. Our data suggests that simultaneous administration of a quadrivalent influenza vaccine and an mRNA anti-SARS-CoV-2 vaccine neither affected the safety of said products nor was associated with a higher risk of SARS-CoV-2 breakthrough infection.

Severe Acute Respiratory Syndrome Coronavirus 2 Vaccine Boosters: An Influenza Vaccine Perspective

Changes to severe acute respiratory syndrome 2 (SARS-CoV-2) vaccine guidance since their initial authorization may lead to confusion and hesitancy. Suggested recommendations for an annual SARS-CoV-2 vaccine naturally draw comparisons with the influenza vaccine program. Considering viral and vaccine characteristics between these pathogens provides an important perspective that can help increase vaccine confidence with SARS-CoV-2 vaccines.

Immunogenicity and safety of inactivated quadrivalent influenza vaccine compared with the trivalent vaccine for influenza infection: an overview of systematic reviews

BACKGROUND

Influenza infection is a highly preventable transmissible viral disease associated with mild upper respiratory symptoms and more severe conditions such as lethal pneumonia. Studies have shown that a broader spectrum influenza vaccine could reduce influenza's burden of disease in low- and middle-income countries. A considerable number of systematic reviews reported that quadrivalent influenza vaccines are considered more effective compared to trivalent vaccines, hence, there is a need for an overview in order to synthesize the current evidence pertaining to the comparison between quadrivalent and trivalent inactivated influenza vaccines.

OBJECTIVE

The aim was to summarize the evidence from systematic reviews that investigated the immunogenicity and safety of the Influenza's inactivated quadrivalent vaccine (QIV) compared to the trivalent vaccine (TIV), in the general population.

METHODS

We searched articles up to December 2022 at: Web of Science, EMBASE, MEDLINE, Cochrane Library, and SCOPUS. The search strategy was conducted following the PICO model. We included systematic reviews comparing the primary outcomes of immunogenicity (seroprotection rate and seroconversion rate) and adverse events using risk ratios. The AMSTAR 2 and ROBIS were used for quality assessments, and GRADE was used for evidence certainty assessments.

FINDINGS

We included five systematic reviews, totalling 47,740 participants. The Quadrivalent Inactivated Influenza Vaccine (QIV) exhibited enhanced immunogenicity in the context of B-lineage mismatch when compared to the Trivalent Inactivated Influenza Vaccine (TIV). While the safety profile of QIV was found to be comparable to that of TIV, the QIV showed a higher incidence of solicited local pain among children and adolescents, as well as an increased frequency of local adverse events within the adult population.

CONCLUSION

Our findings suggest that the QIV provides a superior immunogenicity response compared to the TIV in all age groups evaluated, especially when a lineage mismatch occurred. The safety of QIV was considered similar to the TIV, with no serious or systemic solicited or unsolicited adverse events; tough pain at the injection site was greater for QIV. We recommend caution owing to the high risk of bias in the selection process and no protocol registration.

Immunogenicity and safety of Quadrivalent Influenza HA vaccine compared with Trivalent Influenza HA vaccine and evaluation of Quadrivalent Influenza HA vaccine batch-to-batch consistency in Indonesian children and adults

One of the newest strategies developed by the Global Influenza Strategy has been to broaden the composition of the current influenza vaccine formulations from trivalent products to quadrivalent products. This study aimed to assess the immunogenicity and safety of Quadrivalent Influenza HA vaccine (QIV) compared with Trivalent Influenza HA vaccine (TIV) and to evaluate three consecutive batches of QIV equivalence in Indonesian children and adults. This was an experimental, randomized, double blind, four arm parallel group bridging study involving unprimed healthy children and adults aged 9-40 years. A total of 540 subjects were enrolled in this study and randomized into four arm groups. Each subject received one dose of TIV or QIV with three different batch codes. Serology tests were performed at baseline and 28 days after vaccination. Hemagglutination inhibition (HI) antibody titers were analyzed for Geometric Mean Titer (GMT), seroprotection, and seroconversion rates. Solicited, unsolicited, and serious adverse events were observed up to 28 days after vaccination. A total of 537 subjects completed the study per protocol and were analyzed for immunogenicity criteria. All randomized subjects were analyzed for safety criteria. The percentage of the subjects with anti-HI titer ≥1:40 28 days after QIV vaccination was 99.5% for A/H1N1; 99.5% for A/H3N2; 93.1% for B/Texas, and 99.0% for B/Phuket. The seroprotection, GMT, and seroconversion rates of QIV were not significantly different from those of TIV for the common vaccine strains (p > 0.01) and were significantly different from those of TIV for the added B/Phuket strains (p < 0.01). Most solicited injection-site and systemic reactions with either vaccine were mild to moderate and resolved within a few days. Antibody response to QIV were equivalence among vaccine batches and comparable between age groups for each of the 4 strains. QIV was immunogenic and well-tolerated and had immunogenicity and safety profiles compared with TIV for all common strains. The immunogenicity of the three batches of QIV was equivalent for the four strains. Trial registration. Clinical Trial registration: NCT03336593.

Active surveillance for adverse events of influenza vaccine safety in elderly cancer patients using self-controlled tree-temporal scan statistic analysis

Both cancer patients and the elderly are at high risk of developing flu complications, so influenza vaccination is recommended. We aimed to evaluate potential adverse events (AEs) following influenza vaccination in elderly cancer patients using the self-controlled tree-temporal scan statistic method. From a large linked database of Korea Disease Control and Prevention Agency vaccination data and the National Health Insurance Service claims data, we identified cancer patients aged over 65 who received flu vaccines during the 2016/2017 and 2017/2018 seasons. We included all the outcomes occurring on 1-84 days post-vaccination and evaluated all temporal risk windows, which started 1-28 days and ended 2-42 days. Patients who were diagnosed with the same disease during a year prior to vaccination were excluded. We used the hierarchy of ICD-10 to identify statistically significant clustering. This study included 431,276 doses of flu vaccine. We detected signals for 1 set: other dorsopathies on 1-15 days (attributable risk 16.5 per 100,000, P = 0.017). Dorsopathy is a known AE of influenza vaccine. No statistically significant clusters were found when analyzed by flu season. Therefore, influenza vaccination is more recommended for elderly patients with cancer and weakened immune systems.

Effects of COVID-19 and Influenza Vaccination on Rheumatic Diseases: Results From a Survey of Patient-Reported Outcomes After Vaccination

BACKGROUND

This study aimed to compare the occurrence of adverse events (AEs) and disease flares after vaccination against coronavirus disease 2019 (COVID-19) and influenza in patients with autoimmune rheumatic diseases (ARDs).

METHODS

Between November 2021 and March 2022, a survey was conducted among patients with ARD who received COVID-19 and influenza vaccinations. The questionnaire included 11 mandatory and closed-ended questions, and the following items were collected: medical history, immunization history, type of vaccine, patient-reported AEs, flare-up of the underlying disease after vaccination, and a confirmed diagnosis of COVID-19 or influenza. We compared the occurrence of vaccine-related adverse reactions to the COVID-19 and influenza vaccines based on the survey results. Multivariate logistic regression analysis was used to identify the factors affecting AEs or disease flares and to compare the post-vaccine response to mixed and matched vaccines.

RESULTS

We analyzed 601 adults with ARD who received the COVID-19 vaccine, with a mean age of 49.6 years (80.5% female). A total of 255 participants (42.4%) received a complete course of primary vaccination, 342 (56.9%) completed the booster dose, and 132 (38.6%) received a mixed vaccine. The frequencies of AEs (188 [52.2%] vs. 21 [5.8%]; P < 0.001) and disease flares (58 [16.2%] vs. 5 [1.4%]; P < 0.001) after COVID-19 vaccination were significantly higher than those after influenza vaccination. In the risk factor analysis, previous allergic reaction to other vaccines (odds ratio, 1.95; confidence interval, 1.07-3.70; P = 0.034) was the only factor associated with the occurrence of AEs. There was no difference in the post-vaccine responses between the mixed and matched vaccines.

CONCLUSION

The results of the survey of patients with ARD revealed that patient-reported AEs and underlying disease flares after receiving the COVID-19 vaccine were significantly higher than those after the influenza vaccine.

Association of Influenza Vaccination With Risk of Bell Palsy Among Older Adults in Taiwan

Importance

Annual administration of the influenza vaccine (fluVc) is currently the most effective method of preventing the influenza virus in older adults. However, half of adults older than 65 years remain unvaccinated in Taiwan, possibly because of concern about adverse events, such as Bell palsy (BP). Currently, studies on the association between fluVc and risk of BP are inconsistent.

Objective

To determine whether the incidence of BP increases following fluVc in older adults.

Design, Setting, and Participants

A self-controlled case series study design was used. Days 1 through 7, days 8 through 14, days 15 through 30, and days 31 through 60 following fluVc were identified as risk intervals, and days 61 through 180 were considered the control interval. A total of 4367 vaccinated individuals aged 65 years or older who developed BP within 6 months following fluVc were enrolled. Population-based retrospective claims data were obtained between 2010 and 2017; data were analyzed from April 2022 through September 2022.

Exposure

Government-funded seasonal fluVc.

Main Outcomes and Measures

The outcome of interest was BP onset in risk intervals compared with control intervals. Three or more consecutive diagnoses of BP within 60 days following fluVc were used as the definition of a patient with BP. Poisson regression was used to analyze the incidence rate ratio (IRR) of risk intervals compared with control intervals.

Results

In total, 13 261 521 patients who received the fluVc were extracted from the National Health Insurance Research Database in Taiwan from January 1, 2010, to December 31, 2017. Of those, 7 581 205 patients older than 65 years old met the inclusion criteria. The number of patients with BP diagnosed within 6 months following fluVc enrolled for risk analysis was 4367 (mean [SD] age, 74.19 [5.97] years; 2349 [53.79%] female patients). The incidence rate of BP among all observed fluVc older adults was 57.87 per 100 000 person-years. The IRRs for BP on days 1 through 7, days 8 through 14, and days 15 through 30 were 4.18 (95% CI, 3.82-4.59), 2.73 (95% CI, 2.45-3.05), and 1.67 (95% CI, 1.52-1.84), respectively. However, there was no increase during days 31 through 60 (IRR, 1.06; 95% CI, 0.97-1.16). The postvaccination risk of BP was consistent across all subgroups stratified by sex, age group, and baseline conditions.

Conclusions and Relevance

The present self-controlled case series indicated that the risk of BP in individuals older than 65 years increased within the first month, especially within the first week, following fluVc. But overall, the adverse event rate of BP was low, and considering the morbidity and mortality of influenza infection, the benefits of fluVc still outweigh the risks.

Three seasons of enhanced safety surveillance of a cell culture-based quadrivalent influenza vaccine

The objective of this paper is to summarize annual enhanced safety surveillance activity across three seasons (2019/20-2021/22) for cell culture-based quadrivalent influenza vaccine (QIVc; Flucelvax® Tetra) in all age groups. This activity was conducted in primary care setting in Genoa (Italy) during the seasons 2019/20, 2020/21 and 2021/22. All adverse events registered within the first seven days following immunization were analyzed by season, type, age group and seriousness. Over three seasons, 3,603 QIVc exposures were recorded within the enhanced passive safety surveillance activity. No safety signals were identified. The overall reporting rates of individual case safety reports for the seasons 2019/20, 2020/21 and 2021/22 were 1.75%, 0.48% and 0.40%, respectively. The average number of adverse events per individual case safety report was similar (range 3.3-3.8 adverse events per case report) across the three seasons. Most adverse events were reactogenic in nature. The rate of adverse events was similarly low in all age groups. Enhanced passive safety surveillance activity is a feasible approach for the post-marketing monitoring of seasonal influenza vaccines. Within its limitations, results of this study support the favorable safety profile of QIVc. These safety data could further bolster public trust in influenza vaccines with the goal to increase vaccination uptake in all target groups.

Oral adverse events following COVID-19 and influenza vaccination in Australia

Vaccine hesitancy, spurred by misinterpretation of Adverse Events (AEs), threatens public health. Despite sporadic reports of oral AEs post-COVID-19 vaccination, systematic analysis is scarce. This study evaluates these AEs using the Australian Database of Adverse Event Notifications (DAEN). A secondary analysis of DAEN data was conducted, with the analysis period commencing from the start of the COVID-19 vaccination rollout in February 2021 and the inception of the influenza vaccine database in 1971, both through until December 2022. The focus of the analysis was on oral AEs related to COVID-19 and influenza vaccines. Reports were extracted according to a predefined schema and then stratified by vaccine type, sex, and age. Oral paresthesia was the most common oral AE after COVID-19 vaccination (75.28 per 10,000 reports), followed by dysgeusia (73.96), swollen tongue (51.55), lip swelling (49.43), taste disorder (27.32), ageusia (25.85), dry mouth (24.75), mouth ulceration (18.97), oral hypoaesthesia (15.60), and oral herpes (12.74). While COVID-19 and influenza vaccines shared most oral AEs, taste-related AEs, dry mouth, and oral herpes were significantly more common after COVID-19 vaccination. mRNA vaccines yielded more oral AEs than other types. Females had higher oral AE incidence. Most oral AEs did not differ significantly between COVID-19 and influenza vaccination. However, specific oral AEs, particularly taste-related, dry mouth, and oral herpes, were more prevalent after COVID-19 vaccination compared with seasonal influenza, especially in females and mRNA vaccine recipients.

Immunogenicity and safety of the quadrivalent inactivated split-virion influenza vaccine in populations aged ≥ 3 years: A phase 3, randomized, double-blind, non-inferiority clinical trial

This study aimed to evaluate the immunogenicity non-inferiority and safety of the quadrivalent inactivated split-virion influenza vaccine in participants ≥ 3 years old. A total of 3,328 participants were enrolled. Participants 3-8 years old were administered one or two doses of the investigational vaccine or one dose of the control vaccine, whereas the other participants were administered only one dose of the investigational or control vaccine. The immunogenicity and occurrence of adverse events (AEs) after 30 days of full-course vaccination and serious adverse events (SAEs) within 6 months after full-course vaccination were assessed. The sero-conversion rates (SCRs) of anti-H1N1, H3N2, B(Y), and B(V) antibodies in the test group were 74.64%, 87.40%, 82.66%, and 78.89%, respectively, and their geometric mean titers were 1:250.13, 1:394.54, 1:200.84, and 1:94.91, respectively, which were non-inferior to those in the control group. The SCRs and sero-protection rates in the two-dose group of participants 3-8 years old were greater than those in the one-dose group. The incidences of total AEs and adverse reactions in the test group were 31.6% and 21.7%, respectively, which were close to those in the control group. In the two-dose group, the incidence of adverse reactions was considerably lower in the second dose (5.5%) than in the first dose (14.7%). Most AEs were grade 1 in severity, and no SAEs were recorded. The investigational vaccine had immunogenicity non-inferior to the control vaccine, and two doses were more effective than one dose in participants 3-8 years old, with a good overall safety.Trial registration: CTR20200715.

Association between maternal influenza vaccination and neurodevelopmental disorders in childhood: a longitudinal, population-based linked cohort study

OBJECTIVE

To assess the association between in utero exposure to seasonal inactivated influenza vaccine (IIV) and the risk of a diagnosis of a neurodevelopmental disorder in early childhood.

DESIGN

Retrospective cohort study.

SETTING

Population-based birth registry linked with health administrative databases in Western Australia (WA).

PARTICIPANTS

Singleton, liveborn children born between 1 April 2012 and 1 July 2016 in WA.

EXPOSURE

Receipt of seasonal IIV during pregnancy obtained from a state-wide antenatal vaccination database.

MAIN OUTCOME MEASURES

Clinical diagnosis of a neurodevelopmental disorder was recorded from hospital inpatient and emergency department records. We used Cox proportional hazard regression, weighted by the inverse-probability of treatment (vaccination), to estimate the hazard ratio (HR) of neurodevelopmental disorders associated with in utero exposure to seasonal IIV.

RESULTS

The study included 140 514 children of whom, 15 663 (11.2%) were exposed to seasonal IIV in utero. The prevalence of neurodevelopmental disorders was 5.4%, including mental or behavioural (0.4%), neurological (5.1%), seizure (2.2%) and sleep disorders (2.7%). Maternal IIV was not associated with increased risk of neurodevelopmental disorders (HR 1.00; 95% CI 0.91 to 1.08). Children exposed in the first trimester had a lower risk of seizure disorders (adjusted HR [aHR] 0.73; 95% CI 0.54 to 0.998), and preterm children exposed any time during pregnancy had a lower risk of sleep disorders (aHR 0.63; 95% CI 0.41 to 0.98).

CONCLUSIONS

We did not observe increased risk of neurodevelopmental disorders following in utero exposure to seasonal IIV. Although we observed some evidence for lower risk of seizure and sleep disorders, additional studies are required to confirm.