LONDON (Reuters) – Britain launched a trial on Thursday to assess the immune responses generated if doses of the COVID-19 vaccines from Pfizer Inc and AstraZeneca Plc are combined in a two-dose schedule.
The British researchers behind the trial said that data on vaccinating people with the two different types of coronavirus vaccines can help understand whether vaccines can be applied more flexibly around the world. Initial data on immune responses should be generated in June.
The study will examine the immune responses of an initial dose of the Pfizer vaccine followed by a boost of AstraZeneca, and vice versa, at 4 and 12 week intervals.
Both the mRNA injection developed by Pfizer and Biontech and the adenovirus viral vector vaccine developed by Oxford University and AstraZeneca are being launched in Britain, with an interval of 12 weeks between two doses of the same vaccine.
More vaccines are expected to be added to the study when they are approved and implemented.
Recruitment for the study begins on Thursday, with more than 800 participants expected, the researchers said. This makes it much smaller than the clinical trials that were used to determine the effectiveness of individual vaccines.
The trial will not evaluate the overall effectiveness of the injection combinations, but the researchers will measure the responses of antibodies and T cells, as well as monitor any unexpected side effects.
Matthew Snape, an Oxford vaccinologist who is leading the study, said the initial results may inform the vaccine’s implantation in the second half of the year.
“We will have some results, we hope, until June or next, that will inform the use of booster doses in the general population,” he told reporters.
The study seeks to recruit people over 50 years of age who may be at greater risk than younger people and have not yet been vaccinated.
The injection of AstraZeneca is also being tested in combination with the Russian vaccine Sputnik V, and the head of research at the British pharmaceutical said that further studies on the combination of vaccines should be done.
Reporting by Alistair Smout; Bill Berkrot edition