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Vaccinating against COVID-19 and influenza at the same time is safe, shows NIHR study

ComFluCOV news story

Research funded by the NIHR has found that it is safe for people to receive a flu vaccine at the same time as a COVID-19 vaccine. 

Reported side effects were mainly mild to moderate, and there were no negative impacts on the immune response produced by either vaccine when both were given on the same day, in opposite arms. 97% of the study participants said they would be willing to have two vaccines at the same appointment in the future.

Earlier in the pandemic, it was not known how giving COVID-19 vaccination boosters may fit in with the seasonal flu vaccine programme. The Combining Influenza and COVID-19 Vaccination (ComFluCOV) study, led by researchers at the Bristol Trials Centre, University of Bristol and University Hospitals Bristol and Weston NHS Foundation Trust (UHBW) and supported by the NIHR Local Clinical Research Network (LCRN) West of England looked to establish the safety of co-administering the most widely used COVID-19 and influenza vaccines in the UK. The research aimed to describe the expected side effects and immune responses to the vaccines when they are given together. 

A total of 679 volunteers over the age of 18 and who had already received one dose of either the Pfizer/BioNTech or the Oxford/AstraZeneca COVID-19 vaccine took part in the study, across 12 NHS sites in England and Wales. 

The volunteers were randomly allocated into one of two groups. The first group received their second dose of the COVID-19 vaccine and the flu vaccine at their first study visit, then a saline injection (placebo) at their second visit. The second group received their second dose of the COVID-19 vaccine and a saline injection (placebo) at their first visit and then the flu vaccine at their second visit.

Participants also attended a third study visit to discuss any side effects they experienced following their second appointment and to give a final blood sample. 

The most common side effects were pain around the injection site and fatigue. With some combinations there was an increase in the number of people who reported at least one side effect when both COVID-19 and flu vaccine were given together, but the reactions were mostly mild or moderate.   

Dr Rajeka Lazarus, consultant in infectious diseases and microbiology at UHBW and Chief Investigator for the ComFluCOV study, said: 

“By conducting this study we have been able to establish that it is possible to protect people from both COVID-19 and flu at the same appointment. This is a really positive step which could mean fewer appointments for those who require both vaccines, reducing the burden on those who have underlying health conditions and would usually be offered the influenza vaccine.”

Professor Andrew Ustianowski, NIHR Clinical Lead for the COVID-19 Vaccination Programme and Joint National Infection Specialty Lead, said: 

“This research has quickly provided important and reassuring results that could make vaccination more efficient for both patients and the NHS. I’m proud of NIHR’s role in funding this research that could help to control the COVID-19 pandemic through this upcoming winter.”