What you need to know to take the 4th dose against Covid in SP

The governor of the state of São Paulo, João Doria (PSDB), announced this Wednesday (16) a fourth dose of vaccine against Covid for people over 80 years old.

See what is known so far about how the fourth dose will be applied in São Paulo and understand how this booster has been used in Brazil and in the world.

Who can take the fourth dose in the state of São Paulo? Until now, only immunosuppressed patients were able to receive the new additional dose in São Paulo. From March 21 (next Monday), however, all people over 80 will be able to take the fourth dose of the Covid vaccine in the state.

The application, however, does not have age as the only criterion. In addition to being over 80, the person must also have taken the third dose at least four months ago.

“Why the population aged 80 and over? Because this is the most vulnerable population”, said, this Wednesday afternoon, Regiane de Paula, general coordinator of the State Immunization Program. According to her, this population is estimated at around 900 thousand people in São Paulo.

The indication of this age group is a guideline from the State’s Covid Scientific Committee, which took into account the “high mortality rate among the elderly in this age group during the circulation of the ômicron variant”. The rate “was higher than the deaths that occurred in the two other peaks of the pandemic in 2020 and 2021”, according to the Secretary of State for Health.

Is there a forecast of the fourth dose for other groups in São Paulo? Regiane de Paula also stated, during the announcement this Wednesday, that there is a possibility that the age group for the fourth dose will be expanded to the population over 60 years old.

And the Ministry of Health? What does the federal government say about the fourth dose? The action of the state of São Paulo differs from the orientation of the Ministry of Health. wanted by sheetthe ministry stated that, so far, it recommends a vaccination schedule with three doses and “the booster dose, only for immunosuppressed Brazilians over 12 years of age”.

This group includes, for example, people undergoing chemotherapy, undergoing organ or stem cell transplants, living with HIV/AIDS or undergoing hemodialysis.

THE sheet asked if there is any analysis in progress to expand the recommendation, but received no response until the conclusion of this report.

Which vaccines will be used in SP for the fourth dose? According to what was announced at a press conference on Wednesday, any of the immunizing agents released so far by Anvisa (National Health Surveillance Agency) can be used at this stage of the campaign in São Paulo.

That is, people can receive vaccines from Pfizer, AstraZeneca/Oxford (Fiocruz), Janssen or Coronavac (Butantan).

Should I get a vaccine other than the booster and starting doses? THE sheet asked the São Paulo State Health Department about whether or not to recommend the application of heterologous regimens (when a vaccine different from the one previously received is applied). The secretariat did not respond until the publication of the text.

Will elderly people with comorbidities be prioritized for the fourth dose? THE sheet sought out the Health Department of the state of São Paulo in search of details and did not receive an answer on this point either.

Will all health posts apply the fourth dose? THE sheet contacted the state department and got no response. The municipal secretary was also questioned by the report, but there was no response.

What do the studies say about the need and effectiveness of a fourth dose? So far, there is not enough evidence to support the need for a fourth dose of vaccines broadly, for all people.

In any case, experts have said that it is recommended for people at greater risk of developing severe Covid, such as those with compromised immune systems, including people undergoing cancer treatment, people with HIV/AIDS and transplant recipients. Elderly people, due to immunosenescence, can also benefit from the fourth dose.

A study in Israel, for example, showed that there is an increase in the amount of antibodies after the fourth dose similar to what is observed at the peak with the third dose, but without as much success in preventing infections.

The research looked at 274 healthcare professionals who received three doses of immunizers made with messenger RNA vaccine platforms (Pfizer and Moderna) plus one dose of Pfizer.

Another Israeli study pointed out that the fourth dose of Covid did not prevent the omicron infection, but the short booster period (only one month) may not have been enough to stop the virus from entering.

Other countries are offering the fourth dose to which groups? Last week, France also announced a fourth dose of the Covid vaccine for people over 80 who received the booster dose more than three months ago. The announcement was made after a spike in cases.

In Germany, the vaccination commission recommended a fourth dose, six months after the third, for risk groups, such as those over 70, immunosuppressed, people who live and work in home-rest cases and healthcare professionals.

In the US, Pfizer is seeking FDA clearance for a fourth dose of its vaccine in people age 65 and older.

Israel makes the fourth dose available to all healthcare professionals and people over 60 years of age. Canada offers people over 18 years of age three months after the third dose.

In Denmark, individuals at higher risk and over 60 years of age can take it. Chile, on the other hand, started vaccinating its population aged 55 and over with a fourth dose in February.

More recently, Sweden made the new booster available for seniors over 80, and South Korea for health workers and vulnerable people.

What do we know about the safety profile of the fourth dose? In general, the adverse effects that occur with booster doses of the vaccine are mild, and it is expected that the same will be observed with the application of the fourth dose.

In the Israel study of 274 volunteers, the main adverse events were local (80%), disappearing within two days.

Studies also show that the frequency of post-vaccination adverse events decreases with boosters. This does not mean that they should be neglected.

Does the effectiveness of vaccines decrease over time? What changes with the omicron variant? The studies carried out so far show that two doses of the vaccines or a single dose of Janssen, against the omicron, have reduced efficacy.

According to a survey by the CDC (Centers for Disease Control and Prevention of the United States), the effectiveness of the booster dose drops after four months. Even with the drop, protection remains high, around 78%, says the agency.

A national survey carried out in the United Kingdom pointed out that, in the context of the omicron, the booster dose provides 20 times greater protection for hospitalization and death compared to individuals with only two doses. The age cut was above 50 years.