The UK has drawn up plans that would allow patients to receive different coronavirus vaccines for the first and second doses under certain circumstances, a move that highlights a growing divide in public health policy between the UK and the rest of the West.
The government Green paper for vaccinations says that “every effort” should be made to complete the vaccination course with the same vaccine. But he also says: “For people who have started the schedule and who present for vaccination at a site where the same vaccine is not available, or if the first product received is unknown, it is reasonable to offer a dose of product available locally to complete the schedule. “
Health officials have said this will only happen under very limited circumstances.
The guidelines stress that this would involve people who may be at high risk or unlikely to show up again. The two UK-approved vaccines share the same mode of action, targeting the spike protein of the virus, making it “likely that the second dose will help boost the response to the first dose,” says section.
The Oxford vaccine was approved in late December, when the chapter of the green paper in question, number 14, was updated, according to the government website that hosted it.
Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene and Tropical Medicine, told the Financial Times that the approach was “not supported by evidence from randomized trials.”
He noted, however, that a randomized trial of the vaccine mix had been announced in the UK. The reason why such a trial had been suggested, even before any vaccine was licensed, was that there were “theoretical reasons” to believe that mixing and pairing vaccines might be more effective than that. use of two doses of the same vaccine, he added.
Jonathan Stoye, a virologist at the Francis Crick Institute, said mixing different vaccines on an emergency basis “does not seem unreasonable and is akin to war medicine.” But he added: “This should not become common practice without careful investigation.”
British health officials rejected suggestions that the guidelines implied a change in tactics. One said: ‘The UK has not moved to a mixed regime.’ The approach would be used in exceptional circumstances where the only alternative was to not complete a vaccination program, they said. In practice, it would be rarely used, if at all, added the official.
Importantly, combination trials, including one that studies the AstraZeneca and Sputnik V jabs, are not yet complete, and the UK decision apparently reflects what experts have described as a pragmatic, if “go-it -alone ”, in the middle rapidly increasing number of cases.
The United States Centers for Disease Control, one of the world’s leading public health authorities, says coronavirus vaccines are not interchangeable. The BioNTech and Oxford vaccines use different technologies. The approach also seems discouraged in Europe.
British health officials have said vaccine shortages are a reality that “cannot be avoided” and appear to be pursuing a strategy designed to balance risks and benefits under difficult circumstances.
European authorities do not plan to approve the AstraZeneca vaccine until February because they do not have enough data. US regulators have said the same. Moncef Slaoui, the head of the U.S. Operation Warp Speed, the U.S. government’s effort to manufacture and purchase vaccines for the country, said approval was not expected until April.
Concern is growing over the UK’s decision to change dosing regimens for the two coronavirus vaccines it has approved, as experts question the justification for the long time between the first and second vaccines. US experts said they wouldn’t recommend deviating from what has been tested and tried in trials.