Mixing vaccines generates robust immune system against COVID-19: Oxford study

New Delhi, June 29: Alternating doses of the AstraZeneca and Pfizer-BioNTech vaccines generate a robust immune system against COVID-19, a study conducted by the Oxford University has said.

Mixed schedules of these vaccines induced high concentrations of antibodies against SARC-CoV2 spike IgG protein when doses were administered four weeks apart, the study found. The study was published on the Lancet pre-print server.

Professor Matthew Snape, Associate Professor in Paediatrics and Vaccinology at the University of Oxford, and Chief Investigator on the trial said that 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," Professor Snape also said.

He said that these results are an invaluable guide to the use of mixed dose schedules, b but the interval of four weeks studied here is shorted than the 8-12 week schedule most commonly used for the Oxford AstraZeneca vaccine.

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

"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," he also added.