Amid the second wave of COVID-19, when the world is going through a shortage of vaccine, a study has been conducted by Oxford University which found that alternating doses of the AstraZeneca and Pfizer-BioNTech vaccines generate healthy immune responses against the coronavirus.
According to the study, ‘Mixed’ schedules of these vaccines made high concentrations of antibodies against the SARS-CoV2 spike IgG protein when doses were administered four weeks apart.
This study has been published in the Lancet pre-print server which means all possible vaccination schedules involving the Oxford-AstraZeneca and Pfizer-BioNTech vaccines could potentially be used against coronavirus.
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.”
These results are priceless guide to the use of mixed dose schedules. Nonetheless the interval of four weeks is shorter than the eight-to-12-week schedule that is most commonly used for the Oxford-AstraZeneca vaccine, says the study.
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).
This UK government funding study aims to evaluate the feasibility of using a different vaccine for the initial ‘prime’ vaccination to the follow-up ‘booster’ vaccination.
