Acceptance of COVID-19 and Influenza Vaccine Co-Administration: Insights from a Representative Italian Survey.

Alexander Domnich,Elettra Fallani,Andrea Orsi,Riccardo Grassi,Donatella Panatto,Giancarlo Icardi,Marco Salvatore,Maura Cambiaggi,Roberto Ciccone,Bianca Bruzzone,Alessandro Vasco,Allegra Ferrari

doi:10.3390/jpm12020139

Abstract

Co-administration of coronavirus disease 2019 (COVID-19) and seasonal influenza vaccines has several advantages, has been advocated by various public health authorities and should be seen as an opportunity to increase the uptake of both vaccines. The objective of this survey was to quantify the acceptance of concomitant COVID-19/influenza vaccination and to identify its correlates in a representative sample of Italian adults. Of 2463 participants, a total of 22.9% were favorable to vaccine co-administration, while 16.6% declared their firm unwillingness to receive both vaccines simultaneously. The remaining 60.5% of subjects could be dubbed hesitant to some degree. Compliance with the primary COVID-19 vaccination schedule (adjusted proportional odds ratio (aOR) = 7.78), previous influenza vaccination (aOR = 1.89) and trust in public health institutions (aOR = 1.22) were the main determinants of positive attitudes toward vaccine co-administration. Other significant correlates included age, sex, perceived disease severity and vaccination risk–benefit, being offered a more personalized influenza vaccine and recent seeking for influenza-related information. In Italy, hesitancy toward COVID-19/influenza vaccine co-administration is common and appears to be higher than hesitancy toward either vaccine administered alone. This pattern is multifaceted and requires specific and tailored strategies, with public health institutions playing the central role.

Highlights

The ongoing 2021/2022 Northern Hemisphere season is characterized by the cocirculation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza viruses, as of December 2021 detections of the latter remain relatively low [1].At the population level, the “disappearance” of influenza viruses in the previous season determined a progressive waning of acquired immunity; the susceptible fraction of the population is likely to have increased considerably
The results (Supplementary Table S2) showed no substantial changes, the model fit slightly improved with a reduction of 68 in AIC. This is among the first representative surveys aimed at quantifying people’s willingness to undergo concomitant COVID-19/influenza vaccination and identifying its correlates
Concerning the latter, we found that several determinants of vaccine co-administration were shared with those of either COVID-19 or seasonal influenza vaccination (SIV) administered separately, some specific associations emerged

Summary

Introduction

The ongoing 2021/2022 Northern Hemisphere season is characterized by the cocirculation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza viruses, as of December 2021 detections of the latter remain relatively low [1].At the population level, the “disappearance” of influenza viruses in the previous season determined a progressive waning of acquired immunity; the susceptible fraction of the population is likely to have increased considerably. (COVID-19), the risk of overburdening healthcare systems and the fact that seasonal influenza vaccination (SIV) is among the most effective preventive tools available have prompted a call to increase SIV coverage rates [3,4,5] It has recently been suggested [6,7,8] that SIV may exert non-specific effects on SARSCoV-2-related clinical endpoints. A systematic review and meta-analysis by Wang et al [7] showed a 14% confidence interval (95% CI: 9–19%) reduction in the odds of testing positive for SARS-CoV-2 in subjects vaccinated against influenza These non-specific effects may be ascribable to both innate (induction of trained immunity) and adaptive (e.g., cross-immunity and bystander activation) immune-related mechanisms [8]

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Conclusion