Delaying the second dose of Covid-19 vaccines is “very risky” because efficacy data were based on a specific dosing schedule, an FDA deputy director told CNBC on Thursday.
His comments came after the UK decided to administer the second dose of the coronavirus vaccine 12 weeks after the first dose, deviating from what vaccine representatives recommend. Germany is reportedly considering a similar move, while Denmark agreed to a six-week gap between doses.
Vaccines approved for use in the UK require two doses.
The American pharmaceutical company Pfizer and the German biotechnology company BioNTech recommended that the second dose of their vaccine should be given 21 days after the first. British-Swedish pharmaceutical company AstraZeneca said the vaccine it co – developed with Oxford wants two doses that should be administered one month apart. The UK initially said it would follow that timetable.
It is a very risky venture because if it fails, you are in worse shape.
Norman Baylor
Former FDA director
Any decision to change dosing schedules should be based on data, said Norman Baylor, former director of the U.S. Food and Drug Administration’s vaccine administration and review office.
“It’s very dangerous to try and expand [the gap between two doses] or give a single dose without data, ”he told CNBC’s“ Street Signs Asia ”on Thursday.
“I understand some of the rationale for doing this, but again, it’s not really data-driven,” said Baylor, who is also president and chief executive officer of Biologics Consulting. . “It’s a very risky venture because if it fails, you’re in worse shape.”
The UK’s controversial decision came as the country embarks on a new strain of the faster-spreading coronavirus, although there is no evidence that it is more severe or lethal. Some 62,322 cases were reported Wednesday, and more than 2.8 million people have tested positive for the virus so far, according to government data.
A nurse will be preparing the Oxford-AstraZeneca vaccine at Pontcae Medical Center on 4 January 2021 in Merthyr Tydfil, Wales.
Mata Horwood | Getty Images News | Getty Images
Delaying the second dose of the vaccine means more people will get their first dose, but Baylor said it would be very appropriate to follow the dosing rule from the vaccine effectiveness studies.
“If you don’t have the data, you’re taking a risk there,” he said. “That’s the main point, the risk you take.”