Critical Need for Covid-19 Booster Vaccinations in Vulnerable Groups- Study

Since January, the COVID-19 vaccine, by age and priority groups, has been part of the National Immunization Program. According to Professor Max Igor Banks, an infectious disease specialist at the Hospital das Clínicas (HC) of the Faculty of Medicine (FM) of the University of São Paulo, children up to five years old, as well as seniors over 60 years old and people with comorbidities or who are immunosuppressed, should receive booster shots, which can vary between every six months or every year. He also mentions the importance of vaccinating pregnant women — which also protects the baby for a period of time — or people who have never been vaccinated before.

“The pandemic has changed over time, and prevention, control and guidance strategies have also changed. Now, we are in a phase where COVID is still around, but a large part of the population has already been exposed and vaccinated with the initial vaccines. And the vaccine has also changed, since the omicron variant appeared, there are subvariants, changes on top of this initial virus, and the vaccines are updated. As is more or less the case with the flu, it provides better protection against the virus, which is why some people are advised to continue getting vaccinated,” he adds.

New vaccines

The expert comments that the first vaccines created against COVID-19 were monovalent, and with the emergence of new variants, the vaccines were also updated, creating bivalent immunization models. “After the omicron variant appeared, the vaccines were adapted, but the option was still the type of virus that was the original virus. So, you had the vaccine for the original virus, plus the omicron variant, which is why it was bivalent,” he explains.

However, Moderna’s new Spikevax — which will be used for the government’s immunization program — no longer uses the bivalent model and protects against the latest variant, which has found greater ease of circulation, XBB. Banks states: “Now, the option is to vaccinate with the virus that is most closely related to the one circulating among people, always a strain that was circulating relatively recently to develop the vaccine. But the logic is the same as the Pfizer vaccine, it is also a very effective vaccine that will protect against an evolution of the virus, the omicron.”

Although general vaccination is interesting, the availability of vaccines in the SUS, which includes the government’s immunization project, is only aimed at the groups mentioned above. “Now, we are in a very good time for people to get vaccinated, because there is no intense circulation of the virus. This happened at the beginning of the year, and now we are in a period between crises, so if you get vaccinated, when the virus starts circulating again you will be able to protect yourself a little more. This was very politicized, and what we are really concerned about is people’s health. We still have complications from COVID and the vaccine helps”, he concludes.