The European Medicines Agency (EMA) approved on Monday (4) the third dose of anti-Covid vaccine manufactured by Pfizer for all healthy adults, from 18 years of age. The booster should be taken six months after the second dose.
The agency also recommends a third injection of Pfizer or Moderna vaccines (not used in Brazil) as part of the basic immunization program for vulnerable people, 28 days after the second dose. The third dose of Moderna for healthy people is still under evaluation.
According to the EMA Human Medicines Committee, the recommendation is based on a study that showed an increase in the number of antibodies in people aged 18 to 55 years after the third dose.
The agency notes that there is no evidence that higher levels of antibodies imply more protection in people with weakened immune systems, but said it hopes that the extra dose will help to prevent serious conditions “in at least some patients”.
The third dose for vulnerable patients, including the elderly, was already being applied in some European countries and in the United States. Brazil also decided to reinforce the immunization of the elderly, which has already started to be done in São Paulo.
The European Centers for Disease Control (ECDC) last month published a report recommending the extra dose only for patients with depressed immune systems.
A similar recommendation is adopted by the World Health Organization (WHO). The bodies argue that there is no scientific basis for evaluating the risks and benefits of the third dose in healthy adults.
Inflammatory heart disease is a very rare side effect of Pfizer’s vaccine, but the EMA said there have been no reported cases so far after a third dose of the immunizer. According to the agency, adverse effects “are being monitored carefully”.
The regulator stated that the final decision on whether or not to apply an extra dose must be taken by each national government, as it depends on other factors, such as the situation of the pandemic, stage of vaccination and availability of drugs.