Study to examine possibility of mix and match approach to jabs

A STUDY to establish if the Oxford/Astrazeneca and Pfizer coronavirus vaccines can be safely mixed for the first and second doses will be expanded to include two additional jabs as the Government pledged to ensure all adults are given their first dose by July.

Researchers running the ComCov study, launched in February to investigate alternating doses of the first two jabs to be rolled out across the UK, have announced the programme will be extended to include the Moderna and Novavax vaccines.

Led by the University of Oxford, the extra study will seek to recruit adults aged over 50 who have received their first vaccination in the past eight to 12 weeks.

Matthew Snape, associate professor in paediatrics and vaccinology at the University of Oxford, who is chief investigator on the trial, said: “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.

“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 Covid-19 immunisation course more rapidly.

“This would also create resilience within the system in the event of a shortfall in availability of any of the vaccines in use.”

The researchers will study any adverse reactions and the immune system responses to these new combinations of vaccines.

The study is designed as a so-called non-inferiority study, which means its intent is to demonstrate that mixing is not substantially worse than not mixing.

It will compare the immune system responses to the goldstandard responses reported in previous clinical trials of each vaccine.

Today’s announcement comes as the committee advising Ministers on vaccine use in the UK said it will look “very carefully” at data surrounding the Johnson and Johnson version of the jab after the US recommended its rollout should be paused.

The US is proposing a “pause” in administering the Johnson and Johnson Covid-19 vaccine to investigate reports of potentially dangerous blood clots.

Johnson and Johnson has since confirmed it will delay the rollout of its single-dose vaccine across Europe following the review.

The UK has 30m doses of the inoculation on order, but it has not yet been signed off for use by the Medicines and Healthcare products Regulatory Agency (MHRA).

Despite the concerns, Health Secretary Matt Hancock said the country was “on track to offer a vaccine to all adults by the end of July”.

We are on track to offer a vaccine to all adults by the end of July.

Health Secretary Matt Hancock.