Having Flu and COVID Vaccines at Same Time Is Safe: ComFluCOV Study

Having flu and COVID jabs at the same time is safe, according to preprint research from the ComFluCOV study.

The University Hospitals Bristol and Weston NHS Foundation Trust-led study supports giving COVID booster doses alongside the seasonal flu programme.


Researchers concluded that concomitant vaccination did not raise safety concerns, and the immune response to both vaccines was preserved.

Side effects were reported for some combinations but were found to be mainly mild to moderate, including fatigue, apart from one hospitalisation with severe headache related to the trial.


Study Details 

The trial involved 679 participants across 12 sites. They’d had a first dose of Oxford/AstraZeneca or Pfizer/BioNTech COVID vaccines.

When they had their second dose, they were randomised to also receive one of three different flu jabs or placebo in the other arm (or thigh in some cases).

Three weeks later the initial placebo group had a flu jab, and the flu jabs groups had a placebo.

Side effects were reported for the six possible combinations through electronic diaries.

The authors concluded: “Concomitant vaccination with both COVID-19 and influenza vaccines over the next immunisation season should reduce the burden on the healthcare services for vaccine delivery, allowing for timely vaccine administration and protection from COVID-19 and influenza for those in need.”


Wise and Precautionary Checks 

Commenting via the Science Media Centre, Dr Peter English, retired consultant in communicable disease control, said: “We would not expect any problems to arise from coadministration 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 coadministration. This study does just that.”

The study received Department of Health and Social Care and National Institute for Health Research funding.

Another commenter, Professor Penny Ward, independent pharmaceutical physician, visiting professor in pharmaceutical medicine, King’s College London, said the study helped to answer a question she’d been asking herself.


“It’s not often that a publication is directly relevant to one’s own health decision making. Being a lady of mature years, I have just received my invitation for the annual influenza vaccination, but the set date is a month or so prior to the earliest date I would be called for a COVID vaccine booster. What to do – wait and have them both together or take one then t’other?”

She continued: “I think I can be confident that I can go ahead with my flu shot while waiting to be called up for the COVID vaccine booster. Thanks to the ComCov study team for getting this out into the public domain so I could answer my own question without needing to bother the local GP. Let’s get this out on the airwaves so other members of the public with the same dilemma can be similarly reassured.”

‘The safety and immunogenicity of concomitant administration of COVID-19 vaccines (ChAdOx1 or BNT162b2) with seasonal influenza vaccines in adults: a phase IV, multicentre randomised controlled trial with blinding (ComFluCOV)’ preprint by Rajeka Lazarus et al.

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