The European Medicines Agency (EMA) recommended Monday to administer an extra Pfizer-BioNTech COVID-19 vaccine to people with severely weakened immune systems 28 days after the second dose.
The EMA’s Committee for Human Medicine assessed data on Pfizer-BioNTech booster shots and concluded that it showed “a rise in antibody levels when a booster dose is given approximately six months after the second dose in people from 18 to 55 years old,” the EU regulator said in a statement.
It did not directly advise a third dose for healthy adults.
The scientific body is still evaluating data on Moderna booster shots.
Pfizer-BioNTech vaccines were the first COVID-19 jabs authorized in the European Union, and the bloc financially contributed to the development of the vaccine under an advanced purchase agreement signed in 2020.
This year, Pfizer-BioNTech committed to delivering a total of 600 million vaccine doses to the bloc.
In order to provide booster jabs, the European Commission agreed in May with Pfizer-BioNTech to purchase another 1.8 billion doses for 2022 and 2023.
The vaccine is based on messenger RNA (mRNA), a messenger molecule with instructions to produce a protein from the virus that causes COVID-19 to prepare the body to fight the disease.
Contrary to traditional vaccines, Pfizer-BioNTech’s jab does not contain the virus itself.