French health authorities said on Friday that people under the age of 55 who received a first dose of the AstraZeneca coronavirus vaccine should receive another vaccine for their second dose because of an extremely rare risk of clots.
Germany is expected to recommend a similar strategy to people under 60.
However, the World Health Organization has said it is too early to know whether such a mixture of vaccines should be recommended and the European Medicines Agency has not recommended age restrictions on the use of the AstraZeneca vaccine.
French authorities say the British-Swedish vaccine remains the key to their inoculation plan and have called on the elderly to continue receiving it, as hospitals in the country are struggling with a new increase in COVID-19 patients.
“It is an effective vaccine,” Dominique Le Guludec, president of the French Health Authority, told reporters. “If we want to win the fight against the virus, we have to use all the weapons we have.”
Several European countries have decided in recent weeks to mimic the use of the AstraZeneca vaccine in the elderly due to growing evidence that the vaccine could be linked to rare clots in younger populations.
Since March 19, France has only offered the AstraZeneca vaccine to people over the age of 55.
More than half of France’s population under that age – including Health Minister Olivier Verán – received the first dose of vaccine before that.
The French health authority said on Friday it would maintain the age limit for the time being and recommended that younger people who received the first dose of AstraZeneca vaccine use a second dose of either Pfizer or Moderna.
“It’s a precaution,” Veran told RTL radio.