UK trial testing ‘mix and match’ vaccines to be expanded

In the beginning of the year, the Oxford Vaccine Group launched their Com-Cov vaccine trial to find out whether it was possible to mix and match different vaccines for the first and second jab. The results of the first stage are expected to be revealed next month, but in the meantime the study has been expanded to include new vaccines, Moderna and Novavax.

A new leg

The first phase of the Com-Cov research included 800 participants. Some of them received two doses that were mixed between Pfizer and AstraZeneca, and others got jabbed with the same vaccine twice. For their second leg, the Oxford Group hopes to collect 1050 participants above the age of 50 who have already received their first jab of the AstraZeneca or Pfizer vaccine with the NHS. They have announced that as the situation progresses, and the number of approved vaccines increases, they will be recruiting more volunteers.

Those who agree to participate will be getting their second dose in the trial itself. Participants who got their first dose of AstraZeneca or Pfizer will receive a second dose of either Moderna, Novavax or the same vaccine once again. Of the two new vaccines, Moderna has been approved by theMedicines and Healthcare products Regulatory Agency (MHRA) but Novavax is still waiting to be sanctioned.

Hopes for success

The results of this trial are highly anticipated as experts think that in the future, mixing vaccinations will be inevitable. Professor Jeremy Brown from the UK’s Joint Committee of Vaccination and Immunisation told the BBC:

It's practically going to have to be that way because, once you've completed a course of, say, the Moderna or Pfizer or the AstraZeneca, with two doses - in the future, it's going to be quite difficult to guarantee you get the same type of vaccine again.

Chief Investigator on the trial, Matthew Snape also explained that mixing and matching different vaccines will help speed up the vaccination program around the world. He said:

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.

So far, over 32 million citizens have received their first jab in the UK while over 7 million have been fully vaccinated. But, with the spread of the new variants, and the easing of the lockdown, uncertainty is still in the air.