Oxford finds COVID vaccine mix could give better immunity against virus

London: A study conducted by Oxford University has found out that the mixing of Covid-19 vaccines gives robust protection against the virus.

The study published on the Lancet pre-print server shows that all possible vaccination schedules involving the alternating doses of Oxford-AstraZeneca and Pfizer-BioNTech vaccines could potentially generate robust immune responses against Covid-19.

As per the study, 'mixed' schedules of these vaccines induce high concentrations of antibodies against the SARS-CoV2 spike IgG protein when doses were administered four weeks apart.

Professor Matthew Snape, Associate Professor in Paediatrics and Vaccinology at the University of Oxford, and Chief Investigator on the trial said: "The Com-COV study has evaluated 'mix and match' combinations of the Oxford and Pfizer vaccines to see to what extent these vaccines can be used interchangeably, potentially allowing flexibility in the UK and global vaccine roll-out."

"The results show that when given at a four-week interval both mixed schedules induce an immune response that is above the threshold set by the standard schedule of the Oxford/AstraZeneca vaccine", he added.

Professor Snape said these results are an invaluable guide to the use of mixed dose schedules, but the interval of four weeks studied here is shorter than the eight to 12-week schedule most commonly used for the Oxford-AstraZeneca vaccine.

Meanwhile, UK Deputy Chief Medical Officer Professor Jonathan Van-Tam said: 'Today's data are a vital step forward, showing a mixed schedule gives people protective immunity against Covid-19 after four weeks."

"Our non-mixed (homologous) vaccination programme has already saved tens of thousands of lives across the UK but we now know mixing doses could provide us with even greater flexibility for a booster programme, while also supporting countries which have further to go with their vaccine rollouts and who may be experiencing supply difficulties."

The University of Oxford is leading the Com-COV study, run by the National Immunisation Schedule Evaluation Consortium (NISEC) which aims to evaluate the feasibility of using a different vaccine for the initial 'prime' vaccination to the follow-up 'booster' vaccination.