A new study, published this Wednesday (6) in the New England Journal of Medicine, found that the protection rate of the fourth dose of the Covid-19 vaccine from pharmaceutical Pfizer decreases after one month (four weeks) of application.
However, against severe symptoms, the protection rate was maintained for a month and a half after application.
Using the Israeli Ministry of Health database, researchers extracted information from more than 1.2 million people aged 60 years and older who were eligible for the fourth dose during a period when the Ômicron variant (B. 1.1.529) of SARS-CoV-2 was prevalent in the country between January 10 and March 2, 2022.
They wrote that “the rates of confirmed infections with SARS-CoV-2 and severe Covid-19 were lower after a fourth dose of the Pfizer vaccine than after just three doses. Protection against confirmed infections appeared to be short-lived, while protection against serious illness did not decline during the study period.”
In Brazil, the Ministry of Health recommended the 2nd booster dose against Covid-19 for elderly people over 80 years old. The fourth dose should be taken four months after the first. The orientation is that the second reinforcement is done, preferably, with Pfizer.
The United States also indicated the fourth dose, but the recommendation is for people 50 years of age or older.
Another study published by Israel’s Sheba Medical Center had already found that the fourth dose increases antibodies to even higher levels than the third, but “probably” would not be enough to ward off the highly transmissible Omicron.
Ministry of Health Director-General Nachman Ash described these findings as “unsurprising to some extent” as Omicron infections had been detected in some people after they had received the fourth dose.
But “protection from severe morbidity, especially for the elderly population and population at risk, is still provided by this vaccine (dose) and therefore I urge people to keep coming to be vaccinated,” he told Army Radio.
Source: CNN Brasil
