A study conducted by Novavax has found that co-administering a COVID-19 vaccine with a flu vaccine is safe and effective, with the efficacy of both jabs appearing to be preserved.

The study, co-authored by Seqirus, was conducted as part of a Phase III clinical trial of Novavax’s COVID-19 vaccine NVX-CoV2373 in the UK.

The co-administration sub-study enrolled a total of 431 volunteers, all of whom had received a flu vaccine provided by Seqirus.

Following this, approximately half of the volunteers also received NVX-CoV2373, while the rest received a placebo jab.

The study results, published on the pre-print server medRxiv, suggest that the efficacy of both the flu vaccine and the COVID-19 vaccine appeared to be preserved, with no additional safety concerns appearing with co-administration.

In a statement, Seqirus said certain limitations of the study include the small patient population, the lack of formal pre-specified non-inferiority statistical assessment of immunogenicity and the lack of randomisation in recruiting the sub-study, immunogenicity and reactogenicity cohorts.

"As the next influenza season approaches and people still need a primary COVID-19 vaccine series or a booster, separate healthcare visits to cover both COVID-19 and influenza vaccinations will be burdensome," said Gregory M. Glenn, president of research and development, Novavax.

"As the first clinical study to evaluate safety, immunogenicity, and efficacy of a COVID-19 vaccine when co-administered with a seasonal influenza vaccine, these results demonstrate the promising opportunity for concomitant vaccination, which may improve the uptake of both vaccines,” he added.