British health officials will now allow people to mix COVID-19 vaccines as the pandemic intensifies – but experts warn it can be risky.
The adjustment in the vaccine board, which occurs as the country faces a new highly contagious mutation of the virus, marks a surprising departure from previous guidance – and an entirely different approach to launching the vaccine in the United States, the New York Times reported.
The UK protocol now states that a person can receive their follow-up injection of COVID-19 with a different vaccine candidate for their first dose, if necessary.
Britain has approved two deadly virus vaccines, developed by AstraZeneca and Pfizer.
“For individuals who started the schedule and show up for vaccination in a location where the same vaccine is not available, or if the first product received is unknown, it is reasonable to offer a dose of the product available locally to complete the schedule.” updated guidance states.
However, the protocol reiterates that it is preferable to receive a second dose of the same vaccination, noting that a different inoculation should only be used if the patient is at “immediate high risk” or is considered “unlikely to return”.
“In these circumstances, since both vaccines are based on protein spike, the second dose is likely to help increase the response to the first dose,” he explained.
But the new council still raised eyebrows in the scientific community.
“There is no data on this,” Cornell University vaccine expert John Moore told the Times, adding that UK officials “appear to have abandoned science altogether and are just trying to guess how to get out of the mess.”
The update also contrasts with the guidelines established by the Centers for Disease Control and Prevention in the United States, which explicitly state that vaccines “are not interchangeable”.
“Any of the currently authorized COVID-19 mRNA vaccines can be used where indicated,” wrote the CDC, noting that the Advisory Committee on Immunization Practices “does not declare a product preference.”
“However, these COVID-19 mRNA vaccines are not interchangeable with each other or with other COVID-19 vaccine products,” said the agency. “The safety and effectiveness of a series of mixed products has not been evaluated.”
The CDC goes on to state that if different doses of vaccines are administered “inadvertently”, no additional doses of any of the vaccines should be administered.
When contacted by The Post, the CDC declined to comment on the UK’s updated guidance and would re-evaluate its own guidance in the light of the new council.
The United States has approved two coronavirus vaccines, developed by Pfizer and Moderna.
The UK, which has surpassed 2.5 million confirmed cases of COVID-19, is battling an increase in infections, as a more contagious variant strikes across the country – prompting at least 17 countries to announce a ban on trips to the British.