Nurse Sandra Lindsay receives her second dose of 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 Monday that they have no evidence that their jointly developed vaccine will continue to protect against Covid-19 if the booster vaccine is given later than tested in studies.
“The safety and efficacy of the vaccine were not evaluated on different dosing schedules, as most study participants received the second dose in the window specified in the study design,” the companies said in a joint statement, referring to premiums and a recall shots given at three weeks.
“There is no evidence that protection after the first dose is sustained after 21 days.”
Germany was considering on Monday whether to allow a delay in the administration of the second dose to make the few supplies move on, following a similar move by Britain last week. Separately, Denmark approved a delay of up to six weeks between the first and second vaccines.