Home Top News Understand the importance of taking booster doses of the vaccine against Covid-19

Understand the importance of taking booster doses of the vaccine against Covid-19

Understand the importance of taking booster doses of the vaccine against Covid-19

In the absence of updated guidelines from the Ministry of Health, decisions on the application of booster doses of the vaccine against Covid-19 fall on municipalities and states. With each city using different criteria for the application of vaccines, there is a lack of clarity for Brazilians about the importance of completing their vaccination schedule to contain the new increase in cases of the disease.

The most recent guideline from the federal government on the subject is from June 19 of this year, and establishes that all people over 12 years old can receive a booster dose (or third dose). The second booster dose (fourth dose) is only recommended for people over 40 years of age.

For immunocompromised people, two booster doses are recommended over 12 years of age, and a third booster dose (fifth dose) for those over 40 years of age. These are considered the complete vaccination cycles for each population group.

However, most Brazilian capitals adopt vaccine schemes that are different from this one and different from each other. There are capitals that make the fourth dose available to the entire adult population, and others that are already applying the fifth dose to the elderly and immunosuppressed people over 18 years of age.

Faced with the new high of cases, it is necessary to reinforce the importance of booster doses to contain the advancement of the disease.

According to infectologist Álvaro da Costa, from Hospital das Clínicas, many factors contributed to the increase in cases of Covid: the relaxation of the use of masks, the return of large events with agglomerations, and also the decrease in immunity conferred by vaccines over time. .

With advances in scientific knowledge about immunizers against Covid-19, it has been observed that protection tends to decrease between six and eight months after the application of the two initial doses.

“People lost their fear of the pandemic, because two years have passed, and now the cases of friends who have caught it are milder. Adherence to booster shots is low, as they don’t know the risk they are taking by not getting vaccinated again, ”she said.

According to data released by the Ministry of Health on November 24, more than 77 million Brazilians did not even receive the first booster dose 🇧🇷 Among eligible persons, 24 million missed the second booster dose 🇧🇷

“There is great resistance from the population to taking additional doses due to the improvement in the pandemic scenario. The guidance on the importance of completing the vaccination cycle was left aside, while the discourse that casts doubt on the effectiveness of the vaccine was constant,” said infectologist Raquel Stucchi, from the State University of Campinas (Unicamp).

She criticized the lack of communication from state and municipal management, and the “absence” of the Ministry of Health, which has not given new guidance on reinforcement since June.

Costa recalls the importance of vaccination as a collective measure, since people who have not completed the vaccination schedule are more likely to transmit the virus, including those who are part of the risk groups and may develop severe cases of the disease. “We are no longer talking about controlling an unknown disease. After two years, we have an increase in cases and mortality that could be avoided,” he said.

Experts agree that Brazil is not necessarily lagging behind in the number of recommended booster doses, but rather in the effectiveness of vaccines. Both said that the country should already be applying bivalent vaccines.

bivalent vaccines

Faced with changes in the virus and the possibility of escaping the new lineages to the immune response generated by vaccines developed and in use around the world, pharmaceutical companies started to develop up-to-date immunizers adapted to the most epidemiologically relevant strains, such as BA subvariants. 1, BA.4 and BA.5, by Ômicron.

Reinforcement with Pfizer’s bivalent vaccine against Covid-19, which also includes Ômicron’s BA.4 and BA.5 sublines, for example, presents a significantly superior immune response compared to vaccination with the pharmaceutical’s original immunizer, according to information disclosed by Pfizer.

The National Health Surveillance Agency (Anvisa) authorized the emergency use of the bivalent vaccine on November 22, along with another immunizer that includes the subvariant BA.1. In a note, Pfizer said that updated vaccines should be delivered to Brazil “in the coming weeks”.

However, the Ministry of Health and experts stressed that vaccines that are already applied as a booster remain effective, and that it is not recommended that people wait for the arrival of bivalent vaccines to take their booster dose. Monovalent vaccines continue to protect against severe forms of Covid-19 and the possibility of death.

“We do not have a concrete date forecast or how many bivalent vaccines will arrive in Brazil. The older vaccines are still very important, as they reduce the risk of serious cases”, says Stucchi.

Álvaro da Costa says that the arrival of bivalent vaccines is important, but that the doses are already delayed, as we do not know whether the variants that will be circulating in the coming months will be exactly those against which the vaccine protects.

“We have to understand which variants will be circulating in the country to know the size of the impact of bivalent vaccines”, he concludes.

*With information from Lucas Rocha, Carolina Figueiredo and Beatriz Gabriele

Source: CNN Brasil



Please enter your comment!
Please enter your name here

Exit mobile version