Debate will be held by Ctai, linked to the Ministry of Health
There are still no conclusive studies on the effectiveness of the second booster dose.
Israel expands fourth dose to adults
The Technical Advisory Chamber on Covid-19 Immunization (Ctai) begins to discuss this week the possibility of applying the second booster dose – which would be the fourth dose – of the vaccine against covid-19 in Brazil in the elderly and health professionals.
Ctai was created by the Ministry of Health to help fight the pandemic in the country. A technical note from the folder, issued in December, recommends the fourth dose only for immunosuppressed people, who should receive the vaccine four months after the first booster.
At the moment, Chile and Israel are already adopting the fourth dose and countries such as Germany and the United States are studying the possibility, given the increase in cases promoted by the Ômicron variant.
According to infectious disease specialist Renato Kfouri, director of the Brazilian Society of Immunizations (SBIm), which is also a member of Ctai, the group will analyze whether there is a need for a fourth dose for the elderly and health professionals, in addition to what should be the interval between doses of reinforcement.
Conclusive studies on the need to apply a fourth dose in these groups have not yet been published. The main information comes from Israel, which already vaccinates people over 60 with the fourth dose. In addition, an advisory panel of the Israeli Ministry of Health recommended this Tuesday (25) the second booster dose for all adults, which should be given five months after the third dose.
Israeli researchers found that people who received a fourth dose of the immunizer had three to five times more protection against severe Covid-19 than those who received three doses. According to them, the defense against infection by the virus has increased twice.
For the head of the Department of Infectious Diseases at Unesp, Alexandre Naime Barbosa, “very likely” the fourth dose will be approved.
“Immunocompromised people have difficulty producing antibodies and keeping them longer, which makes the vaccine response less intense and more ephemeral. For the general population, there is no consensus on the need”, he explained to the newspaper O Globo. “The closest to this are the elderly, who to some degree are also immunosuppressed, because they experience immunosenescence. [envelhecimento do sistema imunológico]”.
Meanwhile, epidemiologist Carla Domingues, who coordinated the National Immunization Program (PNI) between 2011 and 2019, believes that it is necessary to wait for the publication of more studies on the subject.
“We are losing focus, not even one stage of vaccination ends and another begins. If evidence emerges that there’s a new variant that requires a fourth dose, that’s what we’ll do. But no studies show this yet.”