They are more than 533,000. Those under 55 who received a first dose of AstraZeneca vaccine between February 6 and March 13. But since March 19, the vaccine has been reserved for people over 55 years old. What then happens for their second dose, which is necessary for the vaccine to be effective?

They will receive a dose of another vaccine, Pfizer or Moderna, said on April 9 the Minister of Health the Minister of Health, Olivier Véran, on RTL. An announcement immediately confirmed by the High Authority of Health (HAS).

Less favorable risk / benefit balance

The restriction to people over 55 years old was decided in response to the rare cases of thrombosis in people vaccinated with this vaccine. The youngest are therefore redirected to other available vaccines because the benefit / risk balance is less favorable for them.

Indeed, the risk is higher – the cases of thrombosis concerned children under 55 years of age – and the benefit of the vaccine lower, because the youngest are less at risk of a severe form of covid.

12 weeks between the two doses

It is completely consistent to say “We do not recommend the AstraZeneca vaccine to people under 55 years of age while waiting to learn more (…) and therefore if you have received a first injection and you are under 55 years old , you will be offered another vaccine at 12 weeks after the first injection, you will receive an injection of a messenger RNA vaccine“, developed the minister.

12 weeks is indeed the expected time between the two doses of AstraZeneca. It remains unchanged, even if the second injection is given with another vaccine.

These 600,000 people will therefore have received a first dose of so-called “viral vector” vaccine and will receive a second dose of a messenger RNA vaccine. A mixture that should ensure long-term immunity against covid.