Skip to content

Oxford Study Says Mixing Covid-19 Vaccines Gives Good Protection

Study finds mixed schedules of the AstraZeneca and Pfizer-BioNTech vaccines generate robust immune responses.

LONDON — Amid the global shortage of the Covid-19 vaccines, a study conducted by Oxford University has found out that alternating doses of the AstraZeneca and Pfizer-BioNTech vaccines generate robust immune responses against the coronavirus.

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

This study — published on the Lancet preprint server — means all possible vaccination schedules involving the Oxford-AstraZeneca and Pfizer-BioNTech vaccines could be used against Covid-19.

“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 U.K. and global vaccine roll-out,” said Matthew Snape, associate professor in Paediatrics and Vaccinology at the University of Oxford, and Chief Investigator on trial.

“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.”

Map of Oxford University UK

To spread the word about the same, the University of Oxford tweeted about it. 

“NEW – An Oxford-led study has found: • Mixed schedules of Oxford/Pfizer vaccines generate strong immune response vs. COVID19 • Immune responses differed according to order of immunization, with Oxford Vaccine followed by Pfizer generating the better immune response,” read the tweet

Professor Snape said these results are an invaluable guide to the use of mixed dose schedules. Still, the interval of four weeks studied here is shorter than the eight to 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,” U.K. Deputy Chief Medical Officer Professor Jonathan Van-Tam said.

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

“We know that the Oxford-AstraZeneca two-dose schedule is highly effective and has helped to save many lives,” Andrew Ustianowski, clinical lead for the Covid-19 vaccination program at National Institute for Health Research and Joint National Infection Specialty Leader, said. 

“The fact we now know it works well, in terms of immune responses, when combined with the Pfizer vaccine provides researchers with the valuable knowledge that these vaccines could be used flexibly for those yet to be vaccinated in the U.K. and globally.”

The University of Oxford is leading the Com-COV study, run by the National Immunisation Schedule Evaluation Consortium. This U.K. government funding study aims to evaluate the feasibility of using a different vaccine for the initial ‘prime’ vaccination to the follow-up ‘booster’ vaccination. 

(With inputs from ANI)

(Edited by Amrita Das and Pallavi Mehra. Map by Urvashi Makwana)

Recommended from our partners