Nurse Sandra Lindsay receives the second dose of a Pfizer coronavirus vaccine (COVID-19) at Long Island Jewish Medical Center on January 4, 2021, in Queens, New York City.
Shannon Stapelton | Getty Images
BioNTech and partner Pfizer warned on Monday that they had no evidence that the jointly developed vaccine will continue to protect against Covid-19 if the booster injection is given later than tested in the tests.
“The safety and efficacy of the vaccine have not been evaluated in different dosing schedules, as the majority of trial participants received the second dose within the window specified in the study design,” said the companies in a joint statement, referring to primer and a booster shot given three weeks apart.
“There is no data to show that protection after the first dose is maintained after 21 days.”
Germany was considering on Monday whether it would allow a delay in administering the second dose to keep scarce supplies going after a similar action by Britain last week. Separately, Denmark approved a delay of up to six weeks between the first and the second injection of the vaccine.