What is the importance of annual double vaccination for SARS-CoV-2 and influenza?

15 May 2023

What the research says

Seasonal influenza and SARS-CoV-2 are both associated with considerable morbidity and mortality and vaccination offers the best protection against both viral illnesses. While the global circulation of influenza was reduced during the COVID-19 pandemic phase, as national ‘lock downs’ have eased and social distancing rules relaxed, circulation patterns are likely to return to at least pre-pandemic levels (McCauley et al 2021).

Concomitant vaccination could reduce burden on health care systems. Concurrent delivery of influenza and SARS-CoV-2 vaccines have been shown to be safe and to offer effective protection (Hause et al 2022; Lazarus et al 2021). Data are also emerging to indicate that influenza vaccination may provide a protective background against both infection with SARS-CoV-19, severe COVID-19 illness and COVID-19-related death (Shosha et al 2022; Su et al 2022; Xie et al 2023; Jiang et al 2022).

For the future, concomitant influenza-COVID-19 vaccines are in development and may support national annual vaccination programmes in achieving the necessary level of population immunity (Shi et al 2022). Concomitant vaccination may be particularly important for vulnerable groups including the elderly and those with multimorbidity.

What this means for your clinical practice

  • Encourage patients to receive their influenza and SARS-CoV-2 vaccinations per National guidelines
  • Reassure patients that studies have confirmed the safety of receiving both vaccinations at the same time and that influenza vaccination may also offer additional protection against SARS-CoV-2 infection and severe COVID-19 illness
  • Ensure patients are up to date with all recommended vaccinations according to National guidelines

Resource information

Respiratory conditions
  • COVID-19
Respiratory topics
  • Vaccination
Type of resource
IPCRG COVID-19 and respiratory Q&A


With grateful thanks to Karin Lisspers, Associate Professor (Family Medicine and Preventive Medicine, Uppsala University, Sweden) for and on behalf of the IPCRG practice driven answers review group.

Useful links and supporting references:

Hause AM, et al. Reactogenicity of simultaneous COVID-19 mRNA booster and influenza vaccination in the US. JAMA Netw Open 2022;5:e2222241.

Lazarus R, et al. Safety and immunogenicity of concomitant administration of COVID-19 vaccines (ChAdOx1 or BNT162b2) with seasonal inlfuenza vaccines in adults in the UK (ComFluCOV): a multicentre, randomised, controlled, phase 4 trial. Lancet 2021;398:2277–87.

McCAuley J, et al. The importance of influenza vaccination during the COVID19 pandemic. Influenza Other Respi Viruses 2022;16:3–6.

Shi R, et al. A combination vaccine against SARS-CoV-2 and H1N1 influenza based on receptor binding domain trimerized by six-helix bindle fusion core. eBioMedicine 2022;85:104297.

Shosha SH, et al. Does influenza vaccination help reduce incidence of COVID-19 infection among hospital employees. Medicine 2022;101:2(e28479).

Su W, et al. The association between previous influenza vaccination and COVID-19 infection risk and severity: A systematic review and meta-analysis. Am J Prev Med 2022;63:121–30.

Xie Z, et al. Association of dual COVID-19 and seasonal influenza vaccination with COVID-19 infection and disease severity. Vaccine 2023;41:875–8.

Jiang B, et al. Association between influenza vaccination and SARS-CoV-2 infection and its outcomes: systematic review and meta-analysis. Chin Med J (Engl) 2022;135:2282–93