Nurse Sandra Lindsay will receive the second dose of a Pfizer vaccine against coronavirus disease (COVID-19) at the Long Island Jewish Medical Center on January 4, 2021 in the Queens Ward, New York City.
Shannon Stapelton | Getty Images
BioNTech and partner Pfizer warned Monday that they had no evidence that their jointly developed vaccine will continue to protect against Covid-19 if the booster shot is given later than tested in trials.
“The safety and efficacy of the vaccine has not been evaluated based on different dosing schedules, as the majority of subjects received the second dose within the time frame specified in the study design,” the companies said in a joint statement, referring to prime and a booster shot three weeks apart.
“There are no data to demonstrate that protection is maintained after the first dose after 21 days.”
Germany considered on Monday to allow a delay in the administration of the second dose in order to further grow scarce supplies after a similar move by Britain last week. Separately, Denmark approved a delay of up to six weeks between the first and second injection of the vaccine.