key: cord-0729806-hbxuroyh
authors: Baj, Andreina; Gasperina, Daniela Dalla; Focosi, Daniele; Forlani, Greta; Ferrante, Francesca Drago; Novazzi, Federica; Azzi, Lorenzo; Maggi, Fabrizio
title: SAFETY AND IMMUNOGENICITY OF SYNCHRONOUS COVID19 AND INFLUENZA VACCINATION
date: 2022-05-07
journal: J Clin Virol Plus
DOI: 10.1016/j.jcvp.2022.100082
sha: 796bfc4d93c5fd07735556cdd48041e3211f0592
doc_id: 729806
cord_uid: hbxuroyh

Given the ongoing COVID19 pandemic, the decline in serological response since dose 2, and the upcoming flu season, COVID19 vaccines will increasingly be administered in combination with vaccines against seasonal pathogens. It is of interest to confirm that concurrent vaccination against influenzavirus has no negative impact on serological response to SARS CoV-2. Anti-Spike IgG and Anti-Receptor Binding Domain (RBD) Neutralizing Antibodies (NAb) in serum was assessed in 64 immunocompetent healthcare workers (HCW) before and 14 days post the third dose of BNT162b2 vaccine (Comirnaty®, Pfizer/BioNTech) or BNT162b2 plus quadrivalent flu vaccine (Vaxigript Tetra ®Sanofi Pasteur) on the same day. We report here safety and efficacy of combined BNT162b2 and flu vaccine in 64 healthcare workers at a single institution. No differences were found in adverse events or anti-Spike antibody levels.

Combining vaccinations against different pathogens has been standard practice for decades in both pediatric and adult patients. Considering the 2021/2022 influenza season, several countries have begun to offer boost doses of COVID19 vaccines [1] [2] [3] . This can be done either alone or in combination with other vaccines such as influenza 4 . Given the ongoing COVID19 pandemic (and the decline in serological response since dose 2) and the upcoming flu season, it is of interest to confirm that concurrent vaccination against influenzavirus has no negative impact on serological response.

In this study, 64 immunocompetent healthcare workers (HCW) employed within the Varese Hospital voluntarily choose to get only the third dose of The clinical protocol for sample and data collection and the informed consent were approved by the Institutional Ethics Committee (Comitato Etico dell'Insubria, n° 165/2020). Table 1 shows the demographic and serological characteristics of participants at baseline, while Table 2 shows the results (increases from baseline) according to the anti-S1/S2 IgG starting level before vaccination. Despite the indication for the third BNT162b2 dose was blinded, 16% of HCW had baseline values that predicted low neutralizing antibody levels. No statistically significant differences were found between the two entire cohorts or sub-cohorts.

Influenzavirus, after its disappearance during the COVID19 pandemic, is now resurfacing thanks to tapering of social isolation measures 6 , and flu vaccine campaigns need to be rapidly implemented to prevent recrudescence of mortality. Preliminary in vitro evidence suggest that co-infection of influenzavirus A aggravates SARS-CoV-2 infection and disease severity 7 . This study has several limitations, including the small sample size, the lack of randomization, and lack of determination of anti-influenza antibody responses. Our preliminary findings nevertheless show that concomitant vaccination has no detrimental impact on safety or immune responses.

Antibody titers before and after a third dose of the SARS-CoV-2 BNT162b2 vaccine in adults aged ≥60 years

Effectiveness of a third dose of the BNT162b2 mRNA COVID-19 vaccine for preventing severe outcomes in Israel: an observational study

Viral loads of Delta-variant SARS-CoV-2 breakthrough infections after vaccination and booster with BNT162b2. Nature medicine

Prevention and control of seasonal Influenza with vaccines: recommendations of the advisory committee on immunization practices

While several manufacturers are developing combined (same-syringe) vaccines, synchronous but different-syringe vaccination seems a safe and effective approach to increase compliance while preserving efficacy.

We declare we have no conflict of interest related to this manuscript.