While the world is vaccinating and fighting new variants of Covid-19, a new trial is trying something that could speed up the process: mix shots.
Patients taking part in a clinical trial launched in the UK on Thursday will receive different vaccines for their first and second doses: the vaccine developed by the University of Oxford and AstraZeneca, followed by that of Pfizer and BioNTech , or vice versa.
The UK Department of Health said it was the first study of its kind – patients usually receive two doses of the same vaccine – and it will help determine the safety of mixed doses in different groups and at different time intervals.
The researchers said they want participants older than 50 and not yet vaccinated to participate in the trial.
The 13-month study, known as ‘Com-Cov’, is expected to report its first findings in the summer. Its data could lead to a change in UK vaccine policy.
In the US, the Centers for Disease Control and Prevention recently changed the guidelines for Covid-19 vaccines, saying that patients can mix the dose of Moderna and Pfizer in “extraordinary situations”.
But the Pfizer and Moderna vaccines are both based on the same messenger RNA, or mRNA, platform. However, the British trial involves mixing vaccines using different techniques. The AstraZeneca / Oxford vaccine uses an inactivated adenovirus, a type of virus that causes colds.
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Participants in the trial will be tested to monitor their levels of antibodies and T cells that search and attack infected cells.
“This is an extremely important clinical trial that will provide us with more important evidence on the safety of these vaccines if used in different ways,” said Nadhim Zahawi, Covid-19 vaccine development minister, in a statement. .
Professor Jonathan Van-Tam, the UK’s deputy general secretary, who is ultimately responsible for the study, said there were ‘definite benefits to having data that could support a more flexible vaccination program.’
“It is also possible that the immune response may be enhanced by the combination of vaccines, which can yield even higher antibody levels that last longer; unless evaluated in a clinical trial, we just will not know,” he added.
The UK has been criticized for delaying the second vaccine dose for some patients by up to 12 weeks instead of the recommended 21 days, in order to prioritize the administration of as many first doses as possible.
But Health Secretary Matt Hancock this week pointed to new research, yet to be judged by peers, suggesting that patients show high immune resistance to Covid and that transmission is reduced to just one dose.
In the United States, vaccine deficiencies and distribution problems have been reported, while many European countries are also receiving far fewer doses than expected.
The Oxford / AstraZeneca vaccine has not yet been approved in the US, despite approval in the UK and elsewhere, although Germany, Sweden, Austria and Poland recommend giving it to those over 65 due to unconvincing trial data.
Phase 3 trial results last week showed that a vaccine developed by Johnson & Johnson and Janssen Pharmaceuticals is effectively protected with one shot against Covid.
The UK has so far vaccinated more than 10 million of its 66 million citizens and its government aims to have vaccinated 15 million by 15 February, including the most vulnerable groups.
With more than 109,000 Covid deaths so far, the UK has the fifth highest number of pandemics in the world.
The four countries with the most deaths, India, Brazil, Mexico and the USA, all have a much larger population.
According to the latest NBC News report, the US death toll is now more than 450,000.
