Germany's vaccine commission STIKO on Thursday said it was recommending the use of AstraZeneca's coronavirus vaccine only for under-65-year-olds, due to insufficient data on its effectiveness on older people.
The panel of scientific experts said the vaccine, jointly developed with the University of Oxford, should only be used for "persons aged 18 to 65 years old based on available data".
"There is currently insufficient data to assess the efficacy of the vaccine for persons aged 65 years and older," it said.
"Other than this limitation, this vaccine is considered appropriate" for usage, according to the recommendation by STIKO.
AstraZeneca's vaccine has not been granted approval yet for general use in the European Union, but the bloc's medicines regulator EMA is poised to authorise it on Friday.
STIKO did not detail the data from clinical trials on the vaccine on older people, but two prominent German media outlets had reported that the efficacy on above-65s was below 10 percent.
The Handelsblatt economic daily had reported Monday that Berlin had estimated the efficacy of the jab among over-65s was just eight percent, citing unnamed sources.
Separately the Bild daily, quoting anonymous sources, said the efficacy rate was at "less than 10 percent".
The reports had been rejected firmly by AstraZeneca as well as by the German health ministry.
"A false claim does not become true just because it is repeated," a German health ministry spokesman said Wednesday, dismissing the reports.
He noted that it is a known fact that the AstraZeneca trials involved fewer older people than other manufacturers'.
But "that the efficacy is only eight percent is incomprehensible and in our view, wrong," he added.
Beyond questions over the efficacy of the vaccine on older people, AstraZeneca is currently embroiled in a row with the European Union after it said it could only supply a quarter of the doses it had promised for the first quarter of 2021.
The pharmaceutical giant's chief executive Pascal Soriot said in an interview on Tuesday that his company was prioritising supplies to Britain, which signed its contract three months before the EU did.
He argued that the firm was only required to make a "best effort" to supply the bloc.
The European Commission erupted in fury, demanding on Wednesday that the British-Swedish company make up for the delays by supplying doses from its UK factories.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)