On Monday 4 October, the European Medicines Agency (EMA) said that a third dose of the Covid-19 vaccines developed by Pfizer/BioNTech (Comirnaty) and Moderna (Spikevax) can be given to immunocompromised people at least 28 days after their second injection.
Studies have shown that the use of an extra dose of these vaccines increases the ability to produce antibodies in patients with weakened immune systems, according to the Agency.
It also stresses the importance of distinguishing between “extra doses” for people with weakened immune systems and “booster doses”, which are intended for people with normal immune systems.
The evaluation carried out by the Agency showed that giving a booster dose of Comirnaty vaccine to people aged 18-55 years, approximately six months after their second injection, increased the level of antibodies.
A third dose of this vaccine may therefore also be considered for 18-55 year olds who are not immunocompromised, the EMA said, stressing that the risk of inflammatory heart disease or other very rare side effects after a booster is unknown at this stage.
However, a booster dose of the Spikevax vaccine is still being evaluated.
The EMA said in early September that it was not convinced of the urgency of giving a third dose to people not at risk (see EUROPE 12782/22). The decision, however, lies with the Member States (see EUROPE 12798/6). (Original version in French by Agathe Cherki)