British health officials will now allow people to mix COVID-19 vaccines while the pandemic rages – but experts warn it could be risky.
The change in vaccine advisory, which comes as the country grapples with a new, highly contagious mutation of the virus, marks a surprising departure from previous guidelines – and a totally different approach to vaccine rollout in the US, the New York Times reported. .
The UK protocol now states that a person can have his or her follow-up COVID-19 shot with a vaccine candidate other than the first dose, if needed.
Britain has approved two vaccines for the deadly bug developed by AstraZeneca and Pfizer.
“For individuals who started the schedule and who are present for vaccination in a site where the same vaccine is not available, or if the first product received is unknown, it is reasonable to offer one dose of the locally available product to treat the vaccine. schedule, “the updated guidance statuses.
However, the protocol reiterates that it is preferable to receive a second dose of the same vaccination, noting that a different vaccination should only be used if the patient is “immediately at high risk” or if “is considered unlikely to occur. will come again “.
“In these circumstances, since both vaccines are based on the spike protein, it is likely that the second dose will help to enhance the response to the first dose,” it explained.
But the new advice has still raised eyebrows in the scientific community.
“There is no data on this at all,” John Moore, a vaccine expert at Cornell University, told the Times, adding that the British officials “seem to have left science completely and are just trying to guess how they get out of a mess. “
The update also contrasts with guidelines set by the U.S. Centers for Disease Control and Prevention, which explicitly state that the vaccines are “not interchangeable.”
“Any of the currently approved mRNA COVID-19 vaccines can be used when indicated,” wrote the CDC, noting that the Advisory Committee on Immunization Practices “does not state product preference.”
“However, these COVID-19 mRNA vaccines are not interchangeable with each other or with other COVID-19 vaccine products,” the agency said. “The safety and efficacy of a series of blended products have not been evaluated.”
The CDC further says that if doses of different vaccines are given “accidentally”, no additional doses of either vaccine should be administered.
When the post reached out, the CDC declined to comment on the UK’s updated guidelines and whether it would reassess its own guidelines in light of the new advice.
The US has signed two coronavirus vaccines developed by Pfizer and Moderna.
The UK, which has surpassed more than 2.5 million confirmed COVID-19 cases, is battling an increase in infections as a more contagious variant crosses the country – prompting at least 17 countries to issue UK travel bans.