It is safe for people to receive a dose of the Covid and flu vaccine at the same time, new research shows, and nor is there any negative impact on the immune response as a result of co-administration.
Scientists behind the Combining Influenza and Covid-19 Vaccination (ComFluCov) study said their findings support government plans to roll out Covid booster jabs alongside flu shots, where it is deemed practical.
A trial led by a team at the University of Bristol showed that the reported side effects of co-administration were mainly mild to moderate, concluding that “concomitant vaccination raises no safety concerns and preserves the immune response to both vaccines”.
Dr Rajeka Lazarus, a consultant in infectious diseases and microbiology, and chief investigator for the ComFluCov study, said the research demonstrated that “it is possible to protect people from both Covid-19 and flu at the same appointment”.
She added: “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.
The results of the study, which has yet to be peer-reviewed, have already been shared with the the Joint Committee on Vaccination and Immunisation and the UK’s medicines regulator.
They were used to help shape preparations for the autumn and winter plan. Under this, more than 50 million Covid booster jabs are to be offered, while some 30 million flu shots will also be rolled out.
As part of the ComFluCov trial, two Covid and three flu vaccines were tested – six combinations in all.
Study participants were over the age of 18 and had already received one dose of either the Pfizer/BioNTech or the Oxford/AstraZeneca jab, and were awaiting their second dose.
A total of 679 volunteers took part in the study across 12 NHS sites in England and Wales.
One group received their second dose of the Covid vaccine and the flu vaccine at their first study visit, then a placebo at their second visit.
A second group received their second dose of the Covid-19 vaccine and a 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 and give a blood sample.
The most common side effects were pain around the injection site and fatigue.
Some combinations saw 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, researchers found.
According to the study, the immune responses to both the flu and Covid-19 vaccine were preserved when given together, and 97 per cent of participants said they would be willing to have two vaccines at the same appointment in the future.
Professor Andrew Ustianowski, clinical lead for the Covid-19 vaccination programme at the National Institute for Health Research (NIHR), said: “This research has quickly provided important and reassuring results that could make vaccination more efficient for both patients and the NHS.”
The study was led by researchers at the Bristol Trials Centre at the University of Bristol and University Hospitals Bristol and Weston NHS Foundation Trust, and supported by the Clinical Research Network West of England.
It was funded by the NIHR, with the results due to be published in The Lancet.
Dr Peter English, a former chair of the BMA Public Health Medicine Committee, said “there is a long history of vaccinating people against more than one disease simultaneously”.
He added: “I cannot think of any examples where co-administration of vaccines is in any way unsafe.
“We would not expect any problems to arise from co-administration of flu and Covid-19 vaccines; but it is wise and precautionary to check for possible problems in clinical trials before authorising or recommending widespread co-administration. This study does just that.”