UK expands Covid-19 mix and match vax trial

London, April 14: A study assessing the benefits of mixing and matching coronavirus vaccines has been extended to include the Moderna and Novavax jabs. The Com-Cov study, led by the University of Oxford, has been investigating the immune responses of volunteers given a dose of the Oxford/AstraZeneca vaccine followed by the Pfizer jab, and vice versa, since February.

Now, an expanded study will seek to recruit adults aged over 50 who have received their first dose in the past eight to 12 weeks to test out the immune response when combined with one of the other vaccines as a second dose.

“The focus of both this and the original Com-Cov study is to explore whether the multiple Covid-19 vaccines that are available can be used more flexibly, with different vaccines being used for the first and second dose, said Matthew Snape, associate professor in paediatrics and vaccinology at the University of Oxford and chief investigator on the trial.

If we can show that these mixed schedules generate an immune response that is as good as the standard schedules, and without a significant increase in the vaccine reactions, this will potentially allow more people to complete their immunisation course more rapidly. This would create resilience within the system in the event of a shortfall in availability of any of the vaccines in use,” he said.