The World Health Organization confirmed Friday that, in the absence of sufficient data, it could not issue a recommendation on taking two different coronavirus vaccines, which France intends to do for those under the age of 55 who have received a first dose of AstraZeneca.

"There is not enough data to clarify whether this is something that can be done," said Margaret Harris, a spokesperson for the World Health Organization during the regular press briefing in Geneva.

WHO experts concluded that the possibility of "changing the vaccine is not something they can recommend in this stage."