UK to trial combining shots

LONDON: The United Kingdom yesterday launched a trial to assess the immune responses generated if doses of the Covid19 vaccines from Pfizer Inc and AstraZeneca Plc are combined in a twoshot schedule.

The UK researchers behind the trial said data on giving two different vaccines could aid understanding of whether shots could be rolled out more flexibly. Initial data on immune responses was expected about June.

The trial will examine the immune responses of an initial dose of Pfizer vaccine followed by a booster of AstraZeneca’s, as well as vice versa, with intervals of four and 12 weeks.

Both the mRNA shot developed by Pfizer and Biontech and the adenovirus viral vector vaccine developed by the University of Oxford and AstraZeneca are being rolled out in the UK, with a 12week gap between two doses of the same vaccine.

Recruitment for the study starts today, and more than 800 participants were expected, the researchers said. That makes it much smaller than the clinical trials used to determine efficacy of the vaccines individually.

The trial will not assess the overall efficacy of the combinations, but will measure antibody and Tcell responses, as well as look for unexpected side effects.

Oxford vaccinologist Matthew Snape, who is leading the trial, said initial results could inform vaccine deployment in the second half of the year.

AstraZeneca’s shot is also being tested in combination with Russia’s Sputnik V vaccine, and the British drugmaker’s research chief has said more studies on combining vaccines should be done. — Reuters