University of São Paulo: “The best vaccine is the one that is available the fastest and that can vaccinate more people”

details on the Coronavac study. Overall vaccine efficacy in research with health professionals on the front line of the pandemic was 50.4% – Photo: reproduction
“The best vaccine is the one that is available the fastest and that can vaccinate more people, and the best way out of the pandemic is to have some reasonably effective and safe vaccine.” The phrase of the doctor and researcher at USP Marcio Sommer Bittencourt reflected the tone that part of the scientific community tries to transmit to the population in relation to Coronavac. Five days after the disclosure of part of the information to the public and four days after the submission to the National Health Surveillance Agency (Anvisa) of the request for its emergency registration, the Butantan Institute presented, this Tuesday (11), more numbers and the vaccine methodology against covid developed with the Sinovac laboratory.


Marcio Bittencourt – Photo: personal archive
On Thursday (7) a press conference reported that the vaccine was 78% effective in preventing relatively mild cases, but that need some kind of medical assistance, and 100% in preventing serious cases, which require hospitalization, as well as Deaths.The overall percentage of effectiveness, which included cases of the disease, at any level of severity, was lacking. This is what, in the study, experts call the “primary outcome”. Taking this into account, the vaccine’s effectiveness is 50.4%. That is, the chance of developing the disease by taking the vaccine, for this study, is about 50% lower for those who were vaccinated when compared to those who were not. And the chance that, even if infected, will not develop severe symptoms requiring assistance or die is 78% less among those who received the vaccine. This last number is what experts call a “secondary outcome” or clinical outcome.

As a favorable point for the vaccine, the director of the study Ricardo Palácios emphasized that the study was designed to be as rigorous as possible, suggesting that the overall effectiveness may have declined as a result. It has been tested on health professionals in direct contact with patients with coronavirus – the number of cases in workers working on the front lines against covid is greater. “If we want to compare the different studies, it is like comparing a person who runs on a flat terrain with someone who runs on a steep terrain full of obstacles. This is what we did: put obstacles in place, ”he said. 12,476 people participated in 16 clinical centers located in eight Brazilian states.


Natalia Pasternak – Photo: personal archive
Present at the event, the president of the Instituto Questão de Ciência (IQC) Natalia Pasternak drew attention to the vaccine’s effectiveness in the “real world”. According to the microbiologist, it would not do to have a vaccine with 90% effectiveness and few people immunized because the vaccine did not reach them. For example, because we don’t have adequate freezers to store them. Natalia stressed that Coronavac has the potential to prevent serious cases and deaths and now it is necessary to invest as soon as possible in an advertising and vaccination campaign.

For her, this vaccine is only the beginning of the end of the pandemic, and preventive measures must continue. Better ones may emerge, including this one that is still being researched, improved. “If this vaccine is the beginning, let’s start!”, He concluded.

Marcio Bittencourt, who is part of the USP University Hospital Clinical and Epidemiological Research Center (HU), also defends the benefits of Coronavac. “For a vaccine developed in one year, which can be produced on a large scale locally, easily distributed without problems, I think it’s a spectacle. Yes, there are others that were better in the surveys, but if you can’t distribute it, there’s no use ”, he says. And illustrates:

“Being simplistic, when vaccinating 1 million with a vaccine that reduces 95%, the maximum you protected was 950 thousand people. But by vaccinating 200 million with a vaccine that reduces 50%, you protect up to 100 million people. And among those who take it, most do not even need a doctor. ”

Safety
In previous steps, scientists had already concluded that Coronavac was safe and effective in producing immunity. Phase 3 was carried out mainly with the aim of knowing whether the immunizer, in fact, prevented a person from getting sick. Even so, any adverse reactions and events with the participants continue to be monitored.

As one more point in favor of product safety, André Siqueira, a Fiocruz researcher who served as the main researcher for the Coronavac study in Rio de Janeiro, points out that the rate of adverse events in the placebo and vaccinated groups were similar, and lower in both groups after the second dose. Among the reactions, pain at the application site, headache and fatigue were reported.

Anvisa has ten days to respond to the request for emergency use, after the delivery of all data. The application for definitive registration in Brazil, according to the director of Butantan, must be made by Sinovac, as well as the application for registration in other countries, as the data are all consolidated. “Sinovac collects the data from the studies and it is she who submits the registration application, initially to MNPA, which is ‘Chinese Anvisa’, and also to Anvisa,” said Dimas Covas.

Detailing the data
During the event this Tuesday, the main figures of the study were presented. In the placebo group, 3.6% of participants had covid-19 (167 out of 4,599). In the vaccinated group, 1.8% got the disease (85 out of a total of 4,653).

In the placebo group, 0.7% (31 participants out of 4,653) needed medical assistance for covid-19. In the vaccinated group, only 0.15% (7 out of 4,599 participants) needed medical assistance. When comparing 0.15%, with 0.7%, we reach the rate of 78% less people developing severe symptoms.



For André Siqueira, the results are positive in preventing infections that overload health services, especially serious infections, so that they can have a relevant impact on public health. “How impactful it will depend on the number of doses made available, the population coverage in different states and the speed of this administration”, factors that, he highlights, are not clear in the immunization plan released by the Ministry of Health.

He explains that the efficacy rate of 78% presented by the Butantan Institute was calculated using the WHO index as the main outcome (see table below) , but considering only a score greater than or equal to 3, comparing the vaccinated group and the non-vaccinated group. vaccinated. “This score goes from 0, which is asymptomatic, to 10, which is death; 2 is the symptomatic patient, but independent; 3 is when the person is confirmed for symptomatic coronavirus infection and needs intervention, but has somewhat lost independence from 2, who is a patient with a mild symptom. ”




André Siqueira – Photo: INI / Fiocruz
The rate of 100% was reached considering the severe forms, above 4, that need hospitalization. In other words, what did not count for 78%, and which had not yet been presented by the government, was group 2, which is a symptomatic infection, but which does not require medical care, and asymptomatic ones .

Coronavac
The Sinovac vaccine is produced with an inactivated virus, unable to cause the disease. When introduced into the body, it activates the immune system so that it recognizes that foreign body and produces antibodies to defend itself.

The tests showed that two doses of Coronavac will be needed – applied at intervals of 21 days to ensure immunity. According to the Secretary of State for Health Jean Gorinchteyn, São Paulo already has 10.8 million doses of the vaccine available, and by the first half of February another 35 million will arrive. Dimas Covas announced that the Butantan Institute has the capacity to produce 1 million vaccines per day.

Governor João Doria said that the first phase of the vaccination campaign should begin on January 25 this year. Health professionals, indigenous and quilombolas will receive the first doses.

Effectiveness takes focus away from other discussions
The doctor and researcher at the Institute of Psychiatry (IPq) at USP José Galucci Neto believes that we are paying close attention to the issue of effectiveness, when this is not a problem. “Our greatest chance of failing will be to turn the vaccine into an effective vaccination program that reaches the population, capillarizes it.”

For him, considering that this will be an immense vaccination campaign, perhaps the largest in the history of the country, the Ministry of Health would have had to mobilize civil society, health professionals and the political class, the federal and state governments, in a cohesive manner. “But so far, there has been no campaign or clarification or mobilization. On the contrary, the messages are always ambivalent, ambiguous. ” For Galucci Neto, everything indicates that the federal government took the risk of not preparing itself, believing that the pandemic in some way was less impactful now or already controlled. Bearing in mind that it did not acquire supplies such as syringes and is depending on stocks that can be used, but would have other vaccine campaigns, such as measles, BCG, that will have to happen in parallel.

“We don’t know how the PNI [National Immunization Program] is doing, how much it has been disrupted, and whether it will have the same power as it had before. At the time of H1N1, the PNI vaccinated 80 million people in three months. But they already had, before the campaign started, 100 million doses of vaccine stored and prepared supplies ”, he recalls. “I think it is unlikely, in the way things are being done, that the Ministry of Health will be able to handle both things in an organized manner.” With all this, the researcher thinks that discussing at this point whether the effectiveness is 50% or 60% ends up being “nitpicky”, even though he has criticisms about the way the state government’s communication about Coronavac was made. “Going over 50%, the Ministry would have to be prepared to start vaccination as soon as Anvisa approves it, but it is not. Honestly,

Comments are closed.