The UK National Health Service has pushed back the window for people to receive the second dose of COVID-19 vaccine made by Pfizer and BioNTech – up to a time when the companies were testing only a small percentage of patients.
The NHS wrote a letter to hospitals that those who would receive their second dose after January 4 had to be scheduled from three weeks to 12, with most recipients booked in the last week of the period. The move would bring the window closer to the timeframe for the newly approved vaccine developed by the University of Oxford and the pharmaceutical company AstraZeneca AZN,
Read: UK now has enough vaccine ‘to cover the entire population’ after approval of AstraZeneca – Oxford COVID-19 vaccine
The NHS said the move would protect the largest number of people in the shortest period of time and have the biggest impact on deaths.
Confirmed cases of coronavirus have increased over the past month, and the UK has said a new variant of the virus that causes COVID-19 is more easily transmitted. Daily business climbed from 12,330 at the end of November to 50,023 on 30 December.
When the British Regulatory Agency for Medicines and Healthcare Products granted the vaccination of the American pharmaceutical company Pfizer PFE emergency approval,
and his German partner BNTX,
it is said that the interval between doses should be at least three weeks, based on analyzes that include patients who received their second vaccination within 19 to 42 days after their first vaccination.
Pfizer said the safety and efficacy of the vaccine had not been tested at the new interval. “Pfizer and BioNTech’s Phase 3 study for the COVID-19 vaccine is designed to evaluate the safety and efficacy of the vaccine according to a two-dose schedule separated by 21 days. The safety and efficacy of the vaccine were not evaluated on different dosing schedules, as the majority of the participants in the trial received the second dose within the window specified in the study design, ”the company said.
Pfizer also noted that there are no data indicating that protection is maintained after 21 days of receiving the first dose.
“Although decisions on alternative dosing regimens rest with health authorities, Pfizer believes that health authorities are critical to overseeing alternative schedules that are implemented and to ensure that each recipient receives the maximum possible protection, which means immunization with two doses of the vaccine, “says Pfizer. A message left behind by BioNTech was not immediately returned.
In the information document that the drug companies provided to the U.S. Food and Drug Administration, they said that about 80% of the patients who received the second dose administered it within ten weeks of receiving the first dose.