One of the countries most seriously affected by the coronavirus ; a tropical city of more than 45,000 inhabitants; and a Chinese serum. These are the ingredients of ‘ Project S ‘, an initiative to immunize an entire population whose results shed very promising light on the possible end of the pandemic.
The experiment in question, carried out by the Butantan Institute, consisted of rapidly immunizing a large part of the population of the city of Serrana (in the state of Sao Paulo, Brazil), in order to be able to study the further development of the pandemic.
To do this, the city was divided into four areas with an equivalent population and the Chinese Coronavac vaccine, from the Sinovac Pharma company, was progressively applied to more than 95% of adults who resided in them. At the same time, the main indicators of epidemiological evolution (number of confirmed infections, deaths, cumulative incidence) were being monitored in order to find the immunization threshold capable of containing the virus.
The researchers found that point was reached by fully vaccinating all adults in three of those areas; that is to say, with 75% of the total of the adults of the locality immunized. With this, a significant decrease in the indicators was achieved, which also extended to unvaccinated adolescents and children.
This decline became even more pronounced when 95% of adults were fully immunized; With this figure, a 95% decrease was achieved in deaths , 86% in hospitalizations, and 80% in symptomatic cases, according to the institute’s own data .
For researchers, this demonstrates the usefulness of the vaccine not only as an individual protection measure, but also as a public health strategy. Epidemiological data were already beginning to decline in a promising way with 50% vaccination, and with 75% the pandemic could be considered controlled , with a significant decrease in unvaccinated groups and even in neighboring populations in which a significant number of residents regularly travel to Serrana.
Furthermore, taking into account the remission of the pandemic among children and adolescents, the study authors concluded that it would not be necessary to vaccinate these population groups in order to safely reopen schools.
The Chinese vaccine
Another key point of the study is the use of the Coronavac vaccine from Sinovac Pharma. The serum is surrounded by a certain controversy, since different studies have placed its efficacy at values as disparate as 50 (precisely, by Brazilian researchers ) and 90%.
Unlike the most popular versions in Spain, such as AstraZeneca, Moderna, Pfizer or Janssen, Sinovac serum is a traditional vaccine, consisting of dead viral particles , which when inoculated into the body cause an immune reaction without the need to expose to the person to the risks of the virus.
Thus, the Butantan researchers found that there were no deaths or hospitalizations among those who received the vaccine; and, in addition, they affirm that it is also effective against the P.1 variant , the so-called “Brazilian”.
A spark of light
As promising as these results are, the truth is that they are an exception in the Brazilian environment . The country continues to grow in infections, and is currently the second in the world in number of deaths (more than 460.00), behind the United States, and the third in number of infections, only behind the United States and India.
Furthermore, the vaccination campaign in the country is progressing slowly due to supply and logistics problems. So much so that a commission has been set up in the Senate to investigate the management of the pandemic by President Jair Bolsonaro , who has spoken out on numerous occasions against restrictions against the pandemic and vaccines.