Once essential, now Coronavac is at risk of being left out in Brazil

A pioneer in the fight against Covid in Brazil, Coronavac may have its days numbered in the country. The immunizer, developed by the Chinese laboratory Sinovac and produced here by the Butantan Institute, played an essential role in the beginning of vaccination against the coronavirus, representing 85% of the doses applied in March 2021, for example.

Gradually, however, it was losing ground to other brands and ended last year accounting for less than 10% of applications in the country.

Now, that rate could decrease even further. This is because on Monday (18) the Minister of Health, Marcelo Queiroga, announced that the use of the immunizing agent will be restricted to children and adolescents aged 5 to 18 years, withdrawing the vaccine from the National Immunization Program (PNI) to the adults.

In addition, studies indicate that the effectiveness of Coronovac as a booster dose against new variants, such as delta and omicron, tends to be lower than that of other manufacturers. Thus, its use in new vaccination campaigns has been ruled out by the federal government and even by the states, with the exception of São Paulo.

This, for example, stopped Butantan’s plans to produce more doses in a new factory in 2021 — about 18 million doses of the immunizer have been stopped at the institute since then.

According to Queiroga, the change occurs because Coronavac has no definitive record of use in Brazil at Anvisa. As the folder announced on Sunday (17), with the end of the state of emergency of the pandemic, only immunizers that have the definitive registration can still be applied.

Coronavac can continue to be applied in the so-called primary scheme, that is, when the person has not yet taken another immunization against Covid. Currently in Brazil, however, there are almost no adults who are in this situation, only children and adolescents.

The minister himself has already said that he will ask the agency to extend for another year the authorization for the use of Coronavac for people aged 5 to 17 years – Anvisa has not yet commented on this. Use in this age group was initially granted by the agency in early 2022.

In a statement, the Butantan Institute said that it had not received information about the change in the state of health emergency or in relation to any public directive, and that it intends to produce the vaccine in its new factory in 2023. Anvisa so that the use of Coronavac is extended to the entire public, including children aged 3 to 5 years”.

For Renato Kfouri, director of the Brazilian Society of Immunizations (SBIm), the new recommendation of the Ministry of Health is correct, and was supported by the Technical Advisory Board of the folder. “With the advance of vaccination, there will hardly be an adult who has not received any dose of the primary regimen. Therefore, the decision to maintain this immunizing agent for the pediatric population is right,” he says.

For Kfouri, the immunizer must find it difficult to obtain the definitive record from Anvisa. Therefore, if there is no government interest in obtaining more doses for childhood vaccination, it makes no sense for Coronavac to be purchased in the future.

“The definitive registration was obtained after the presentation of published clinical studies, and Sinovac has no interest in continuing these studies. Therefore, I think it is difficult for this vaccine to be incorporated into the definitive list in the country”, he evaluates.

Anvisa informed, in a note, that it is the producing companies that must request the definitive registration, and that so far Butantan has not made the request.

During the pandemic, the use of the immunizer was full of ups and downs, and it ended up being the subject of a dispute between the then governor of São Paulo, João Doria (PSDB), and President Jair Bolsonaro (current PL).

Still in 2020, the announcement of the purchase by the São Paulo government generated a reaction from the federal government, which first denied its inclusion in the national plan. Afterwards, then Health Minister Eduardo Pazuello said he would buy 46 million doses of Coronavac, but was disallowed the next day by the president.

Thus, the vaccine took another two months to be included in the PNI, which only happened on December 15, 2020.

But the difficulties continued. Doria, who is currently a pre-candidate for the presidency, announced that he would start vaccinating in São Paulo with Coronavac on January 25, 2021, the day of the city’s anniversary, without first having permission from Anvisa.

At that time, the agency awaited the completion of phase 3 clinical trials of the immunizer, conducted in Brazil with 12,000 participants. The problem is that the study did not reach the minimum number of cases necessary to calculate the effectiveness rate.

Thus, it was only on January 7, 2021 that the vaccine’s effectiveness of 50.38% was announced, ten days from the date set for Anvisa to analyze a possible emergency authorization. Amid the political war, Bolsonaro mocked the relatively low value compared to other immunizers.

Even so, Anvisa granted authorization for the vaccine on January 17, 2021. Minutes after the announcement, nurse Mônica Calazans, who worked in the ICU of the Instituto de Infectologia Emílio Ribas (in São Paulo) was the first person in the national territory to receive Coronavac.

Soon the immunizer started to be applied to millions of people across the country, being the main vaccine used in the first stages of the national campaign, which included health professionals and the elderly.

“Coronavac saved millions of lives in Brazil and was very important, and I still think it could continue to be used in our favor”, says Gustavo Cabral, a researcher at the Institute of Biomedical Sciences at USP.

It was thanks to the vaccine that the country reduced the moving average of deaths between January and May. In addition, the study developed by Butantan in Serrana, known as Project S, pointed to an effectiveness (effectiveness in real life) of reducing deaths by Covid by 95%.

“This study was fantastic, and these are the data that Butantan should have presented to Anvisa to obtain the definitive record”, analyzes Cabral.

However, the arrival of new variants, mainly delta and omicron, undermined the effectiveness of all immunizers, and the drop seemed to be greater with inactivated vaccines, as is the case with Coronavac.

Because of this, the application of a third dose began to be recommended in people over 60 from September. The Ministry of Health recommended that the booster be done preferably with Pfizer, AstraZenca or Janssen —which are more effective as a booster—, but the São Paulo government decided to keep the use of Coronavac in the elderly.

The lack of efficacy data in the elderly against the new variants and the studies demonstrating lower effectiveness in this group began to raise questions again about the use of the vaccine in this population.

For specialists, the use of the immunizing agent as a booster in the elderly should not be encouraged, and that is why its use has cooled down. “São Paulo was wrong again when announcing the fourth dose for people over 60 years with ‘any immunizing agent available'”, evaluates Kfouri.

Cabral reinforces that the important thing would be to include all available immunizing agents. “We are not going to control the pandemic only with the vaccination of a group x or y, but of all. [vacinais]and not deleting, seems to me a better strategy.”