A single blinded, phase IV, adaptive randomised control trial to evaluate the safety of coadministration of seasonal influenza and COVID-19 vaccines (The FluVID study)

Co-Administration of BNT162b2 COVID-19 and Influenza Vaccines in Adults: A Global Systematic Review

BACKGROUND/OBJECTIVES

Co-administration of BNT162b2 with licensed seasonal influenza vaccines (SIVs) is recommended by health authorities. We provide a comprehensive summary of the data supporting this practice in adults.

METHODS

This systematic review consolidates available evidence on the prevalence, safety, immunogenicity, efficacy, and effectiveness of co-administering BNT162b2 and SIVs. Searches were conducted for English studies in adults ≥ 18 years of age between January 2021 and August 2024, with no geographic restriction. Study quality was assessed using Cochrane RoB 2.0 and the Newcastle-Ottawa Scale.

RESULTS

Twenty studies (15 observational and 5 clinical trials) were included, mainly conducted in seven countries in Europe and North America. Eight observational studies reported prevalence, twelve reported safety/reactogenicity, six reported immunogenicity, and three evaluated efficacy/effectiveness. Reported co-administration of BNT162b2 vaccines with SIVs increased over time. Of persons receiving BNT162b2, the proportion that reported co-administered SIVs increased from 2.7% in 2021 to 34.1% in 2023. Although variability in outcomes was observed, no consistent pattern indicating a negative impact on immunogenicity from same-day co-administration was identified. Effectiveness was not observed to change when BNT162B2 was co-administered with SIVs. The incidence of systemic and local adverse events was comparable between individuals receiving the vaccines separately and those receiving them co-administered.

CONCLUSIONS

The findings from this review indicate that the co-administration of BNT162B2 with SIVs is both safe and effective. This highlights the value of co-administration, which could enhance vaccine uptake by streamlining immunization protocols and reducing health visits.

Co-administration of seasonal quadrivalent influenza and COVID-19 vaccines leads to enhanced immune responses to influenza virus and reduced immune responses to SARS-CoV-2 in naive mice

The ongoing co-circulation of influenza viruses and severe acute respiratory disease coronavirus 2 (SARS-CoV-2) presents significant public health challenges. Vaccination is a pivotal tool to tackle infections and severe disease. Administering both the influenza and coronavirus disease 2019 (COVID-19) vaccines simultaneously could simplify vaccine delivery and is already practice in several countries. In this study, we assessed the protective efficacy and humoral immune responses elicited by concomitant administration of a quadrivalent influenza vaccine (QIV) and the Pfizer-BioNTech mRNA COVID-19 vaccine (BNT162b2) in naïve BALB/c mice. We included three ways of co-administration: a) both vaccines at contralateral limbs, b) both vaccines at ipsilateral limbs and c) admixture of the two vaccines before administration. The last regimen was included since it has been shown that the lipid nanoparticles used for mRNA vaccines can also have an adjuvant effect on protein-based antigens. Notably, co-administration of QIV and COVID-19 mRNA vaccine led to significantly higher hemagglutinin inhibiting (HAI) and binding antibody titers compared to QIV only vaccination, especially in the ipsilateral and admixed groups. Conversely, ipsilateral administration and administration of an admixed vaccine had a slightly negative impact on SARS-CoV-2 binding and neutralization titers. These findings support the hypothesis that the co-administration of QIV and COVID-19 mRNA vaccines can induce robust antibody responses, which are indicative of protective immune responses against both infectious agents.

The Impact of Vaccination on COVID-19, Influenza, and Respiratory Syncytial Virus-Related Outcomes: A Narrative Review

Vaccination represents a core preventive strategy for public health, with interrelated and multifaceted effects across health and socioeconomic domains. Beyond immediate disease prevention, immunization positively influences downstream health outcomes by mitigating complications of preexisting comorbidities and promoting healthy aging. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza virus, and respiratory syncytial virus (RSV) are common respiratory viruses responsible for broad societal cost and substantial morbidity and mortality, particularly among at-risk individuals, including older adults and people with frailty or certain comorbid conditions. In this narrative review, we summarize the overall impact of vaccination for these 3 viruses, focusing on mRNA vaccines, each of which exhibits unique patterns of infection, risk, and transmission dynamics, but collectively represent a target for preventive strategies. Vaccines for COVID-19 (caused by SARS-CoV-2) and influenza are effective against the most severe outcomes, such as hospitalization and death; these vaccines represent the most potent and cost-effective interventions for the protection of population and individual health against COVID-19 and influenza, particularly for older adults and those with comorbid conditions. Based on promising results of efficacy for the prevention of RSV-associated lower respiratory tract disease, the first RSV vaccines were approved in 2023. Immunization strategies should account for various factors leading to poor uptake, including vaccine hesitancy, socioeconomic barriers to access, cultural beliefs, and lack of knowledge of vaccines and disease states. Coadministration of vaccines and combination vaccines, such as multicomponent mRNA vaccines, offer potential advantages in logistics and delivery, thus improving uptake and reducing barriers to adoption of new vaccines. The success of the mRNA vaccine platform was powerfully demonstrated during the COVID-19 pandemic; these and other new approaches show promise as a means to overcome existing challenges in vaccine development and to sustain protection against viral changes over time.A graphical abstract and video abstract is available with this article.

No immunological interference or concerns about safety when seasonal quadrivalent influenza vaccine is co-administered with a COVID-19 mRNA-1273 booster vaccine in adults: A randomized trial

The objective of the study was to assess the safety and immunogenicity of mRNA-1273 COVID-19 booster vaccination when co-administered with an egg-based standard dose seasonal quadrivalent influenza vaccine (QIV). This was a phase 3, randomized, open-label study. Eligible adults aged ≥ 18 years were randomly assigned (1:1) to receive mRNA-1273 (50 µg) booster vaccination and QIV 2 weeks apart (Seq group) or concomitantly (Coad group). Primary objectives were non-inferiority of haemagglutinin inhibition (HI) and anti-Spike protein antibody responses in the Coad compared to Seq group. 497/498 participants were randomized and vaccinated in the Seq/Coad groups, respectively. The adjusted geometric mean titer/concentration ratios (95% confidence intervals) (Seq/Coad) for HI antibodies were 1.02 (0.89-1.18) for A/H1N1, 0.93 (0.82-1.05) for A/H3N2, 1.00 (0.89-1.14] for B/Victoria, and 1.04 (0.93-1.17) for B/Yamagata; and 0.98 (0.84-1.13) for anti-Spike antibodies, thus meeting the protocol-specified non-inferiority criteria. The most frequently reported adverse events in both groups were pain at the injection site and myalgia. The 2 groups were similar in terms of the overall frequency, intensity, and duration of adverse events. In conclusion, co-administration of mRNA-1273 booster vaccine with QIV in adults was immunologically non-inferior to sequential administration. Safety and reactogenicity profiles were similar in both groups (clinicaltrials.gov NCT05047770).