What are the effects of the influenza vaccine on COVID-19 risk?

Bottom Line:

The influenza vaccine does not increase the risk of non-influenza respiratory viruses (NIRV), including seasonal coronaviruses, in Canada.

Reference:

Skowronski, D.M. et al. Influenza vaccine does not increase the risk of coronavirus or other non-influenza respiratory viruses: retrospective analysis from Canada, 2010-11 to 2016-17.Clinical Infectious Diseases (2020). DOI:10.1093/cid/ciaa626

Date Published:

22 May 2020

Synopsis:

This study examined the relationship between influenza vaccination and the risk of non-influenza respiratory viruses (NIRV), including seasonal coronaviruses, in Canada from 2010 to 2017. Researchers wondered whether fighting influenza could give the body cross-immunity towards coronaviruses, and sought to see if getting the influenza vaccine therefore increased one’s risk for NIRV. During the study, there were 4,281 influenza, 2,565 NIRV, 3,841 negative specimens (for both classes), and 175 co-infections. The adjusted odds ratio (aOR) for influenza vaccination among influenza cases when compared to test-negative controls was 0.55. The aOR for influenza vaccination among coronavirus cases compared to coronavirus test-negative controls was 1.04. The influenza vaccine reduced risk of influenza by >40% while having no impact on the risk of infection from NIRV or seasonal coronavirus.

Summary by: David Lee