Reactogenicity of Simultaneous COVID-19 mRNA Booster and Influenza Vaccination in the US

Trends in the administration of COVID-19 vaccines with other vaccines in the United States reported to V-safe during December 14, 2020-May 19, 2023

Introduction COVID-19 vaccines may be administered with other vaccines during the same healthcare visit. COVID-19 monovalent (Fall 2021) and bivalent (Fall 2022) vaccine recommendations coincided with annual seasonal influenza vaccination. Data describing the frequency of the co-administration of COVID-19 vaccines with other vaccines are limited. Methods We used V-safe, a voluntary smartphone-based U.S. safety surveillance system established by the CDC, to describe trends in the administration of COVID-19 vaccines with other vaccines reported to V-safe during December 14, 2020 - May 19, 2023. Results Of the 21 million COVID-19 vaccinations reported to V-safe, 2.2% (459,817) were administered with at least 1 other vaccine. Co-administration most frequently occurred during the first week of October 2023 (27,092; 44.1%). Most reports of co-administration included influenza vaccine (393,003; 85.5%). Co-administration was most frequently reported for registrants aged 6 months-6 years (4,872; 4.4%). Conclusion Reports of co-administration to V-safe peaked during October 2023, when influenza vaccination most often occurs, possibly reflecting increased opportunities for multiple vaccinations and greater acceptability of the co-administration of COVID-19 vaccine with other vaccines, especially influenza vaccine.

Assessing the determinants of influenza and COVID-19 vaccine co-administration decisions in the elderly

This research examines the low rate of co-administration of influenza and COVID-19 vaccines among seniors aged 65 and older in Korea, despite recommendations from authorities and academia worldwide. The study aimed to understand the influence of general characteristics and health beliefs on the vaccination choices of seniors, who were categorized into four groups based on their vaccination status: influenza only, COVID-19 only, both, or neither. A total of 400 participants, aged 65 and above, were selected through proportional stratified random sampling from five major Korean regions for a survey conducted between November 24th and December 15th, 2023. The results indicated no significant differences in general characteristics across these groups. However, regarding the health beliefs showed significant differences in perceived susceptibility and self-efficacy between the influenza-only and co-administration groups. Higher levels of perceived susceptibility and self-efficacy were associated with choosing co-administration. Contrary to previous studies focusing on safety concerns as a primary factor in vaccine hesitancy, this study highlights the role of individual health-related beliefs, particularly perceived susceptibility and self-efficacy, as critical in influencing the decision for co-administration among the elderly in Korea.

Safety Assessment of Concurrent Vaccination with the HPV Vaccine and the COVID-19 Vaccine in Fujian Province, China: A Retrospective Study

During acute respiratory infections, women may concurrently receive human papillomavirus (HPV) and respiratory vaccines, as observed during the coronavirus disease 2019 (COVID-19) pandemic in China. However, few studies have assessed the safety of such concurrent administration, which could impact HPV vaccination schedules. This study analyzes the safety and optimal sequence of concurrent HPV and COVID-19 vaccinations. For this purpose, we surveyed women with both vaccines from January to October 2023 in Fujian Province, China. During this process, we collected vaccination history and adverse event (AE) data via telephone or interviews. Participants were grouped as Before, Concurrent, or After based on their vaccination sequence. A Chi-squared test, exact Fisher tests, and logistic regression were used to analyze the incidence of AEs and factors influencing vaccine safety. Overall, 1416 eligible participants were included. Although overall AE risk with the HPV vaccine was unaffected by vaccination sequence, individual AEs varied statistically between groups, including pain at the vaccination site (p < 0.001) and prolonged menstruation duration (p = 0.003). Based on the results, the optimal sequence would be to receive the HPV vaccine after the COVID-19 vaccine (After group). This insight may guide future emergency vaccination sequences for HPV and other respiratory infectious diseases.

COVID-19 Vaccination Strategies in the Endemic Period: Lessons from Influenza

Coronavirus disease 2019 (COVID-19) is a highly contagious zoonotic respiratory disease with many similarities to influenza. Effective vaccines are available for both; however, rapid viral evolution and waning immunity make them virtually impossible to eradicate with vaccines. Thus, the practical goal of vaccination is to reduce the incidence of serious illnesses and death. Three years after the introduction of COVID-19 vaccines, the optimal vaccination strategy in the endemic period remains elusive, and health authorities worldwide have begun to adopt various approaches. Herein, we propose a COVID-19 vaccination strategy based on the data available until early 2024 and discuss aspects that require further clarification for better decision making. Drawing from comparisons between COVID-19 and influenza vaccination strategies, our proposed COVID-19 vaccination strategy prioritizes high-risk groups, emphasizes seasonal administration aligned with influenza vaccination campaigns, and advocates the co-administration with influenza vaccines to increase coverage.

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.

Short-Term Adverse Effects of the Fourth Dose of Vaccination against COVID-19 in Adults over 40 Years of Age

Booster vaccines are a strategy to mitigate the conditions in the health, social, and economic fields that the COVID-19 pandemic has brought. A series of adverse effects have been observed since the first vaccination. The present investigation aims to describe the short-term adverse effects of the fourth dose against COVID-19 in adults older than 40 from a region of Peru. The study population was over 40 years of age at the COVID-19 vaccination center in Trujillo, Peru. A 21-day follow-up was conducted from vaccination with the fourth dose, considering sex, age, body mass index, comorbidities, history of COVID-19 infection, vaccination schedule, and simultaneous vaccination against influenza as variables of interest. Multinomial logistic regression with robust variance was used to estimate the risk ratio (RR). In total, 411 people were recruited, and it was found that 86.9% of the participants presented adverse effects after injection with the fourth dose of the vaccine against COVID-19. Pain at the injection site was the most reported symptom after 3 days. Assessment of adverse effects after 3 days found that age ≥ 60 years was associated with a lower likelihood of adverse effects compared to those younger than 60 years (RRc: 0.32; 95% CI: 0.0.18-0.59), males compared to females were associated with a lower likelihood of adverse effects (RRc: 0.54; 95% CI 0.30-0.98), being overweight (RRc: 2.34; 95% CI: 1.12-4.89), and last vaccine with Pfizer-BioN-Tech (RRc: 0.42; 95% CI: 0.18-0.96). Associated adverse effects are mild to moderate. Injection site pain and general malaise are the most frequent adverse effects.

Concurrent Administration of COVID-19 and Influenza Vaccines Enhances Spike-Specific Antibody Responses

Background

The bivalent COVID-19 mRNA boosters became available in fall 2022 and were recommended alongside the seasonal influenza vaccine. However, the immunogenicity of concurrent vs separate administration of these vaccines remains unclear.

Methods

Here, we analyzed antibody responses in health care workers who received the bivalent COVID-19 booster and the influenza vaccine on the same day or on different days through systems serology. Antibody-binding and functional responses were characterized at peak responses and after 6 months following vaccination.

Results

IgG1 and neutralization responses to SARS-CoV-2 XBB.1.5 were higher at peak and after 6 months following concurrent administration as compared with separate administration of the COVID-19 and influenza vaccines. While similar results were not observed for influenza responses, no interference was noted with concurrent administration.

Conclusions

These data suggest that concurrent administration of these vaccines may yield higher and more durable SARS-CoV-2 neutralizing antibody responses while maintaining responses against influenza.

COVID-19 Vaccine Safety Technical (VaST) Work Group: Enhancing vaccine safety monitoring during the pandemic

During the COVID-19 pandemic, candidate COVID-19 vaccines were being developed for potential use in the United States on an unprecedented, accelerated schedule. It was anticipated that once available, under U.S. Food and Drug Administration (FDA) Emergency Use Authorization (EUA) or FDA approval, COVID-19 vaccines would be broadly used and potentially administered to millions of individuals in a short period of time. Intensive monitoring in the post-EUA/licensure period would be necessary for timely detection and assessment of potential safety concerns. To address this, the Centers for Disease Control and Prevention (CDC) convened an Advisory Committee on Immunization Practices (ACIP) work group focused solely on COVID-19 vaccine safety, consisting of independent vaccine safety experts and representatives from federal agencies - the ACIP COVID-19 Vaccine Safety Technical Work Group (VaST). This report provides an overview of the organization and activities of VaST, summarizes data reviewed as part of the comprehensive effort to monitor vaccine safety during the COVID-19 pandemic, and highlights selected actions taken by CDC, ACIP, and FDA in response to accumulating post-authorization safety data. VaST convened regular meetings over the course of 29 months, from November 2020 through April 2023; through March 2023 FDA issued EUAs for six COVID-19 vaccines from four different manufacturers and subsequently licensed two of these COVID-19 vaccines. The independent vaccine safety experts collaborated with federal agencies to ensure timely assessment of vaccine safety data during this time. VaST worked closely with the ACIP COVID-19 Vaccines Work Group; that work group used safety data and VaST's assessments for benefit-risk assessments and guidance for COVID-19 vaccination policy. Safety topics reviewed by VaST included those identified in safety monitoring systems and other topics of scientific or public interest. VaST provided guidance to CDC's COVID-19 vaccine safety monitoring efforts, provided a forum for review of data from several U.S. government vaccine safety systems, and assured that a diverse group of scientists and clinicians, external to the federal government, promptly reviewed vaccine safety data. In the event of a future pandemic or other biological public health emergency, the VaST model could be used to strengthen vaccine safety monitoring, enhance public confidence, and increase transparency through incorporation of independent, non-government safety experts into the monitoring process, and through strong collaboration among federal and other partners.

Overview of COVID-19 Infection, Treatment, and Prevention in Children

Coronavirus disease 2019 (COVID-19), caused by the novel respiratory virus-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-was declared a global pandemic by the World Health Organization on 11 March 2020. Since then, substantial gains have been made in our understanding of COVID-19 epidemiology, disease presentation, and management. While children tend to have less severe disease courses compared to adults, children can still develop severe COVID-19 infections, particularly in those with underlying medical conditions such as obesity, chronic lung disease, or prematurity. In addition, children are at risk of severe complications of COVID-19 infection, such as multisystem inflammatory syndrome in children (MIS-C) or long COVID. The case definitions of MIS-C and long COVID have continued to evolve with the increased understanding of these new entities; however, improved methods of diagnosis and determination of the optimal management are still needed. Furthermore, with the continued circulation of SARS-CoV-2 variants, there remains a need for clinicians to remain up-to-date on the latest treatment and prevention options. The purpose of this review is to provide an evidence-based review of what we have learned about COVID-19 in children since the start of the pandemic and how best to counsel children and their families on the best methods of prevention.

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.

Co-administration of SARS-CoV-2 and influenza vaccines in healthcare workers: Results of two vaccination campaigns in a large teaching hospital in Rome

The concurrent administration of COVID-19 and influenza vaccines has arisen as a promising approach to bolster protection against respiratory pathogens and improve vaccination rates. However, there remains a lack of data regarding the prevalence of co-administration across several vaccination campaigns, especially among healthcare workers (HCWs). Therefore, this study aims to shed light on the acceptance of co-administration strategies among HCWs during the two campaigns following the introduction of the anti-SARS-CoV-2 vaccine. A retrospective cohort study was conducted among the HCWs of the Fondazione Policlinico Universitario "A. Gemelli" IRCCS, a research hospital in Rome. Hospital administrative databases were accessed to gather information about vaccination for SARS-CoV-2 and influenza during the 2021/2022 and 2022/2023 vaccination campaigns. The study included 7399 HCWs. The co-administration of anti-SARS-CoV-2 and influenza vaccines presented a significant rise in 2022/2023 compared to the previous vaccination campaign (+38%): this was confirmed for every professional category, with the largest increases among resident doctors (+47%) and physicians (+44%), and also for every age category, but it was particularly evident for the youngest health professionals. The probability of co-administration uptake during the 2022/2023 campaign was significantly higher for males, and for those that received co-administration during the 2021/2022 campaign, while the probability was lower for nurses and administrative staff. This study highlights the co-administration procedure as a valuable and effective tool in annual vaccination campaigns for SARS-CoV-2 and influenza. The procedure's safety and streamlined logistics make it increasingly attractive for implementation, particularly among HCWs.

Effectiveness of influenza vaccination against coronavirus disease (COVID)-19 outcomes in hospitalized individuals in Brazil: an epidemiological study

OBJECTIVES

This study aimed to evaluate the impact of the flu vaccination on the mortality of hospitalized individuals with coronavirus disease (COVID)-19 in Brazil.

STUDY DESIGN

A retrospective cohort study was conducted based on epidemiological data released by the Brazilian Ministry of Health.

METHODS

An observational study was performed using epidemiological data available at OpenDataSUS. The primary outcome was death-the study period comprised December 29, 2019, to April 6, 2023. The odds ratio with a 95% confidence interval (OR; 95% CI) was calculated to evaluate the association between the epidemiological markers, including the vaccination status against influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and the outcome using a multivariable analysis.

RESULTS

The study comprised 791,891 hospitalized individuals with COVID-19. In the study, male sex, older age, living in rural areas, and race (Black and Indigenous peoples), as well as the presence of clinical signs, comorbidities (except the presence of asthma, which was protective), need for intensive care unit, and invasive mechanical ventilation, were associated with a higher chance of death; the vaccination was protective. Among patients with COVID-19, the individuals who received vaccination against influenza [N = 138,564; OR = 0.754 (95% CI = 0.742-0.766)], SARS-CoV-2 [N = 114,628; OR = 0.630 (95% CI = 0.620-0.641)], or both vaccines [N = 55,616; OR = 0.544 (95% CI = 0.531-0.556)], when compared to the individuals who received no vaccination (N = 483,083), had a lower chance of death.

CONCLUSIONS

The flu vaccination might be responsible for decreased mortality in hospitalized patients with COVID-19 in Brazil.

Estimated Effectiveness of Coadministration of the BNT162b2 BA.4/5 COVID-19 Vaccine With Influenza Vaccine

Importance

No data comparing the estimated effectiveness of coadministering COVID-19 vaccines with seasonal influenza vaccine (SIV) in the community setting exist.

Objective

To examine the comparative effectiveness associated with coadministering the BNT162b2 BA.4/5 bivalent mRNA COVID-19 vaccine (BNT162b2-biv [Pfizer BioNTech]) and SIV vs giving each vaccine alone.

Design, Setting, and Participants

A retrospective comparative effectiveness study evaluated US adults aged 18 years or older enrolled in commercial health insurance or Medicare Advantage plans and vaccinated with BNT162b2-biv only, SIV only, or both on the same day between August 31, 2022, and January 30, 2023. Individuals with monovalent or another brand of mRNA bivalent COVID-19 vaccine were excluded.

Exposure

Same-day coadministration of BNT162b2-biv and SIV; receipt of BNT162b2-biv only (for COVID-19-related outcomes) or SIV only (for influenza-related outcomes) were the comparator groups. For adults aged 65 years or older, only enhanced SIVs were included.

Main Outcomes and Measures

COVID-19-related and influenza-related hospitalization, emergency department (ED) or urgent care (UC) encounters, and outpatient visits.

Results

Overall, 3 442 996 individuals (57.0% female; mean [SD] age, 65 [16.7] years) were included. A total of 627 735 individuals had BNT162b2-biv and SIV vaccine coadministered, 369 423 had BNT162b2-biv alone, and 2 445 838 had SIV alone. Among those aged 65 years or older (n = 2 210 493; mean [SD] age, 75 [6.7] years; 57.9% female), the coadministration group had a similar incidence of COVID-19-related hospitalization (adjusted hazard ratio [AHR], 1.04; 95% CI, 0.87-1.24) and slightly higher incidence of emergency department or urgent care encounters (AHR, 1.12; 95% CI, 1.02-1.23) and outpatient visits (AHR, 1.06; 95% CI, 1.01-1.11) compared with the BNT162b2-biv-only group. Among individuals aged 18 to 64 years (n = 1 232 503; mean [SD] age, 47 [13.1] years; 55.4% female), the incidence of COVID-19-related outcomes was slightly higher among those who received both vaccines vs BNT162b2-biv alone (AHR point estimate range, 1.14-1.57); however, fewer events overall in this age group resulted in wider CIs. Overall, compared with those who received SIV alone, the coadministration group had a slightly lower incidence of most influenza-related end points (AHR point estimates 0.83-0.93 for those aged ≥65 years vs 0.76-1.08 for those aged 18-64 years). Negative control outcomes suggested residual bias and calibration of COVID-19-related and influenza-related outcomes with negative controls moved all estimates closer to the null, with most CIs crossing 1.00.

Conclusions and Relevance

In this study, coadministration of BNT162b2-biv and SIV was associated with generally similar effectiveness in the community setting against COVID-19-related and SIV-related outcomes compared with giving each vaccine alone and may help improve uptake of both vaccines.

Role of Immunoglobulin A in COVID-19 and Influenza Infections

Immunoglobulin A (IgA) is critical in the immune response against respiratory infections like COVID-19 and influenza [...].

mRNA-based vaccines and therapeutics: an in-depth survey of current and upcoming clinical applications

mRNA-based drugs have tremendous potential as clinical treatments, however, a major challenge in realizing this drug class will promise to develop methods for safely delivering the bioactive agents with high efficiency and without activating the immune system. With regard to mRNA vaccines, researchers have modified the mRNA structure to enhance its stability and promote systemic tolerance of antigenic presentation in non-inflammatory contexts. Still, delivery of naked modified mRNAs is inefficient and results in low levels of antigen protein production. As such, lipid nanoparticles have been utilized to improve delivery and protect the mRNA cargo from extracellular degradation. This advance was a major milestone in the development of mRNA vaccines and dispelled skepticism about the potential of this technology to yield clinically approved medicines. Following the resounding success of mRNA vaccines for COVID-19, many other mRNA-based drugs have been proposed for the treatment of a variety of diseases. This review begins with a discussion of mRNA modifications and delivery vehicles, as well as the factors that influence administration routes. Then, we summarize the potential applications of mRNA-based drugs and discuss further key points pertaining to preclinical and clinical development of mRNA drugs targeting a wide range of diseases. Finally, we discuss the latest market trends and future applications of mRNA-based drugs.

Recommendations for Prevention and Control of Influenza in Children, 2023-2024

This technical report accompanies the recommendations of the American Academy of Pediatrics for the routine use of influenza vaccine and antiviral medications in the prevention and treatment of influenza in children during the 2023-2024 season. The rationale for the American Academy of Pediatrics recommendation for annual influenza vaccination of all children without medical contraindications starting at 6 months of age is provided. Influenza vaccination is an important strategy for protecting children and the broader community against influenza. This technical report summarizes recent influenza seasons, morbidity and mortality in children, vaccine effectiveness, and vaccination coverage, and provides detailed guidance on vaccine storage, administration, and implementation. The report also provides a brief background on inactivated and live-attenuated influenza vaccines, available vaccines this season, vaccination during pregnancy and breastfeeding, diagnostic testing for influenza, and antiviral medications for treatment and chemoprophylaxis. Strategies to promote vaccine uptake are emphasized.

Concurrent administration of COVID-19 and influenza vaccines enhances Spike-specific antibody responses

The bivalent COVID-19 mRNA boosters became available in fall 2022 and were recommended alongside the seasonal influenza vaccine. However, the immunogenicity of concurrent versus separate administration of these vaccines remains unclear. Here, we analyzed antibody responses in healthcare workers who received the bivalent COVID-19 booster and the influenza vaccine on the same day or different days. IgG1 responses to SARS-CoV-2 Spike were higher at peak immunogenicity and 6 months following concurrent administration compared with separate administration of the COVID-19 and influenza vaccines. These data suggest that concurrent administration of these vaccines may yield higher and more durable SARS-CoV-2 antibody responses.

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.

Safety and Immunogenicity of the BNT162b2 Vaccine Coadministered with Seasonal Inactivated Influenza Vaccine in Adults

INTRODUCTION

Vaccination is a critical tool for preventing coronavirus disease 2019 (COVID-19) and influenza illnesses. Coadministration of the COVID-19 vaccine, BNT162b2, with seasonal inactivated influenza vaccine (SIIV) can provide substantial benefits, including streamlining vaccine delivery.

METHODS

In this phase 3 study, healthy 18- to 64-year-olds who had received three previous doses of BNT162b2 were randomized (1:1) to the coadministration group (month 0, BNT162b2 + SIIV; month 1, placebo) or the separate-administration group (month 0, placebo + SIIV; month 1, BNT162b2). The primary immunogenicity objective was to demonstrate that the immune responses elicited by BNT162b2 and SIIV [measured by full-length S-binding immunoglobulin G (IgG) levels and strain-specific hemagglutination inhibition assay (HAI) titers against four influenza strains 1 month post-vaccination, respectively] when coadministered were noninferior to those elicited by either vaccine administered alone, based on a prespecified 1.5-fold noninferiority margin [lower bound 95% CI for geometric mean ratio (GMR) > 0.67]. Reactogenicity and adverse event (AE) rates were evaluated.

RESULTS

Randomized participants who received study vaccination (N = 1128; coadministration group, n = 564; separate-administration group, n = 564) had a median age of 39 years. Model-adjusted GMRs for coadministration to separate administration were 0.83 (95% CI 0.77, 0.89) for full-length S-binding IgG levels and 0.89-1.00 (lower bound of all 95% CIs > 0.67) for the four influenza strain-specific HAI titers, with all endpoints achieving the prespecified noninferiority criterion. Reactogenicity events were mostly mild or moderate when BNT162b2 was coadministered with SIIV. Serious AEs were reported in < 1% of participants within 1 month after any vaccination; none were considered vaccine-related.

CONCLUSIONS

BNT162b2 coadministered with SIIV elicited immune responses that were noninferior to those elicited by BNT162b2 alone and SIIV alone, and BNT162b2 had an acceptable safety profile when coadministered with SIIV. The results of this study support the coadministration of BNT162b2 and SIIV in adults.

TRIAL REGISTRATION

ClinicalTrials.gov registration: NCT05310084.

Uneventful Coadministration of Seasonal Influenza and COVID-19 BNT162b2 Vaccines Two Weeks Post-Influenza Vaccination in an Egg-Allergic Subject: A Case Report

The COVID-19 pandemic took the world by storm, and although it has taken the world's attention, it did not stop the spread of other communicable diseases. Seasonal influenza is a viral infection that could cause severe disease; therefore, annual influenza vaccination is highly recommended, especially among patients with a weakened immune system. However, such vaccination is contraindicated for people with hypersensitivity to the vaccine or any of its components, e.g., eggs. This paper describes a case of an egg-allergic individual who received an influenza vaccine containing egg protein, which only caused mild tenderness at the site of injection. Two weeks later, the subject received a double vaccination of a second booster dose of Pfizer-BioNTech and the seasonal influenza vaccine. The patient reported no local or systemic adverse reactions to the vaccine. This case report suggests vaccination safety for subjects with mild allergies to vaccine components.

Safety of co-administration of mRNA COVID-19 and seasonal inactivated influenza vaccines in the vaccine adverse event reporting system (VAERS) during July 1, 2021-June 30, 2022

BACKGROUND

COVID-19 vaccines may be co-administered with other recommended vaccines, including seasonal influenza vaccines. However, few studies have evaluated the safety of co-administration of mRNA COVID-19 and seasonal influenza vaccines.

OBJECTIVE

To describe reports to the Vaccine Adverse Event Reporting System (VAERS) after co-administration of mRNA COVID-19 and seasonal influenza vaccines.

METHODS

We searched the VAERS database for reports of adverse events (AEs) following co-administration of mRNA COVID-19 and seasonal influenza vaccines and following a first booster dose mRNA COVID-19 vaccine alone, during July 1, 2021-June 30, 2022. We assessed the characteristics of these reports and described the most frequently reported MedDRA preferred terms (PTs). Clinicians reviewed available medical records for serious reports and reports of adverse events of special interest (AESI) and categorized the main diagnosis by system organ class.

RESULTS

From July 1, 2021 through June 30, 2022, VAERS received 2,449 reports of adverse events following co-administration of mRNA COVID-19 and seasonal influenza vaccines. Median age of vaccinees was 48 years (IQR: 31, 66); 387 (15.8%) were classified as serious. Most reports (1,713; 69.3%) described co-administration of a first booster dose of an mRNA COVID-19 vaccine with seasonal influenza vaccine. The most common AEs among non-serious reports were injection site reactions (193; 14.5%), headache (181; 13.6%), and pain (171; 12.8%). The most common AEs among reports classified as serious were dyspnea (38; 14.9%), COVID-19 infection (32; 12.6%), and chest pain (27; 10.6%).

DISCUSSION

This review of reports to VAERS following co-administration of 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 disease) was expected. CDC will continue to monitor the safety of co-administration of mRNA COVID-19 and seasonal influenza vaccines, including co-administration involving bivalent mRNA COVID-19 booster vaccines that have been recommended for people ages ≥ 6 months in the United States.

Association of dual COVID-19 and seasonal influenza vaccination with COVID-19 infection and disease severity

The clinical guideline states that COVID-19 vaccination can be administered concurrently with Influenza (flu) vaccination (dual vaccination). Using data from the 2021 National Health Interview Survey, we conducted descriptive analysis and multivariate logistic regressions to examine the association between dual vaccination status and self-reported COVID-19 infection and severity. Among 21,387 (weighted 185,251,310) U.S. adults, about 22% did not receive either the flu or COVID-19 vaccine, 6.0% received the flu vaccine only, 29.1% received the COVID-19 vaccine only, and 42.5% received both vaccines. In the multivariate analysis, individuals with dual vaccination (OR, 0.65, 95% CI, 0.56-0.75) and COVID-19 vaccine only (OR, 0.71, 95% CI, 0.61-0.82) were significantly less likely to report COVID-19 infection when compared with those unvaccinated. There was no significant difference in self-reported COVID-19 symptom severity by vaccination status. The results suggest that dual vaccination may be an effective strategy to reduce the contagious respiratory disease burden.

Adverse reactions in young children receiving the coronavirus disease 2019 vaccine

BACKGROUND

We sought to investigate the occurrence of adverse reactions in Japanese children aged 6 months to 4 years who received the BNT162b2 coronavirus disease 2019 (COVID-19) vaccine, to examine parental considerations, and to evaluate potential risk factors associated with post-vaccination fever.

METHODS

This cross-sectional survey study targeted 1617 children aged 6 months to 4 years who received their primary doses of BNT162b2 from November 10, 2022, to April 30, 2023, in Okayama Prefecture. We surveyed the occurrence of local and systemic reactions within 1 week after vaccination, and described the incidence proportions of adverse reactions for 515 participants overall and by age group. The study also examined the impact of previous COVID-19 infection and co-administration of the seasonal influenza vaccine on post-vaccination fever. A survey also assessed parents' reasons for vaccinating their children and the sources of information they used.

RESULTS

Adverse reactions were infrequent (5.2%, with fever ≥37.5°C; no cases exceeded 39°C) and did not increase with vaccine doses administered. The risk of post-vaccination fever was not statistically associated with a history of COVID-19-the adjusted risk ratio (aRR) was 0.99, and the 95% confidence interval (CI) was 0.41-2.39-but was associated with co-administration of the seasonal influenza vaccine (aRR 3.24, 95% CI 1.14-9.18). Parental decisions regarding vaccination were influenced by official government guidelines and primary care physicians' opinion.

CONCLUSION

This study provides valuable insight into the safety profile of the BNT162b2 vaccine in Japanese children aged 6 months to 4 years. Further research involving larger cohorts and appropriate control groups is needed.

Coadministration of seasonal influenza and COVID-19 vaccines: A systematic review of clinical studies

The lifting of non-pharmaceutical measures preventing transmission of SARS-CoV-2 (and other viruses, including influenza viruses) raises concerns about healthcare resources and fears of an increased number of cases of influenza and COVID-19. For the 2021-2022 influenza season, the WHO and >20 European countries promoted coadministration of influenza and COVID-19 vaccines. Recently, the French Health Authority recommended coupling the COVID-19 vaccination with the 2022-2023 influenza vaccination campaign for healthcare professionals and people at risk of severe COVID-19. The present systematic review examines published data on the safety, immunogenicity, efficacy/effectiveness, and acceptability/acceptance of coadministration of influenza and COVID-19 vaccines. No safety concerns or immune interferences were found whatever the vaccines or the age of vaccinated subjects (65- or 65+). No efficacy/effectiveness data were available. The results should reassure vaccinees and vaccinators in case of coadministration and increase vaccine coverage. Healthcare systems promoting coupled campaigns must provide the necessary means for successful coadministration.