The UK’s National Health Service has shifted the time for people to receive the second dose of the COVID-19 vaccine made by Pfizer and BioNTech – to a time when the companies were testing on only a small percentage of patients.
The NHS wrote a letter to hospitals stating that those scheduled to receive their second dose after Jan. 4 should be moved from three weeks to 12, with most recipients booked in the last week of that time frame. The move would bring the window closer to the time frame for the newly approved vaccine from the University of Oxford and pharmaceutical company AstraZeneca AZN,
Read: UK now has enough vaccine ‘to cover the whole population’ following AstraZeneca-Oxford COVID-19 vaccine approval
The NHS said the move would protect the greatest number of at-risk groups in the shortest period of time and have the greatest impact on the death rate.
Confirmed cases of coronavirus have increased over the past month, with the UK saying a new variant of the virus that causes COVID-19 is more easily transmissible. The number of daily cases has increased from 12,330 at the end of November to 50,023 on December 30.
When the U.K. Regulatory Authority for Emergency Medicines and Healthcare Products approved the vaccine from U.S. pharmaceutical company Pfizer PFE,
and its German partner BNTX,
it said the interval between doses should be at least three weeks, and is based on analyzes that include patients who received their second vaccination within 19 to 42 days of their first vaccination.
Pfizer said the vaccine’s safety and efficacy has not been tested with the new interval. “The Phase 3 study by Pfizer and BioNTech for the COVID-19 vaccine was designed to evaluate the safety and efficacy of the vaccine on a 2-dose schedule separated by 21 days. The safety and efficacy of the vaccine have not been evaluated on the basis of different dosing schedules as the majority of subjects received the second dose within the time frame specified in the study design, ”the company said.
Pfizer also noted that there is no data to show that protection lasts for 21 days after receiving the first dose.
While decisions about alternative dosing regimens lie with the health authorities, Pfizer believes it is critical that health authorities oversee any alternative schedules that are being implemented and to ensure that each recipient receives the maximum possible protection, meaning immunization with two doses of the vaccine, “Pfizer said. A message left with BioNTech was not immediately returned.
In the briefing paper that the pharmaceutical companies provided to the U.S. Food and Drug Administration, they said that about 80% of patients who received the second dose received it within 10 weeks of receiving the first.