BioNTech and partner Pfizer warned on Monday that they had no evidence thattheir jointly developed vaccine will continue to protect against COVID-19 if the booster shot is given later than tested intrials.
"The safety and efficacy of the vaccine has not beenevaluated on different dosing schedules as the majority of trialparticipants received the second dose within the windowspecified in the study design," the companies said in a jointstatement, referring to prime and a booster shots given threeweeks apart.
"There is no data to demonstrate that protection after thefirst dose is sustained after 21 days."
Germany was considering on Monday whether to allow a delay in administering the second dose to make scarce supplies gofurther after a similar move by Britain last week. Separately, Denmark approved a delay of up to six weeks between the firstand second shots of the vaccine
