The eighth and final stage of the Serial Seroepidemiological Survey to Monitor the Prevalence of SARS-CoV-2 Infection in the city of São Paulo (SoroEpi MSP) showed that 98.2% of the adult population in São Paulo already have antibodies against the covid-19 virus. . Samples were collected from March 31 to April 9.
The project, which monitored the frequency of individuals with antibodies against the new coronavirus, was a collaboration between scientists and doctors with funding from Grupo Fleury, Ipec – Inteligência em Pesquisa e Consultoria, Instituto Semeia and Todos pela Saúde.
“As long as vaccination continues at the current rate, it is likely that the pandemic in the city of São Paulo will continue on a downward trajectory, but not in the number of cases, which will still rise several times over. For epidemiologists, normally, two to three peaks should occur per year”, said biologist Fernando Reinach, one of those responsible for the project. According to Reinach, the trajectory is downward in the sense that there are no overcrowded hospitals, a large number of hospitalized people, nor a large number of deaths.
The study revealed that 79.1% of adults in São Paulo have already been infected with the disease. In the previous stage, the percentage was 52.8%. On this data, which identifies the presence of antibodies against the nucleoprotein of the virus, the research showed that there are more cases among the low-income population. While 72% of higher-income people from São Paulo contracted the virus, 84.7% of those with lower incomes were infected.
“Seen since Phase 2, this result has remained. People who live in the poorest areas of the city find it more difficult to protect themselves against the virus, they are forced to live where infection is easier. The difference has been decreasing, it has varied, but it has existed from the beginning,” added Reinach.
The study also indicates that 96.3% of the adult population have neutralizing antibodies against the original variant. Against the Ômicron variant, it is 83.1%. “Our previous results always showed that our numbers were three, four, five times higher than the registered cases, which is to be expected, because they have a lot of asymptomatic cases, or with few symptoms, [em] what [a pessoa] don’t go to the hospital. Of practically 2 million that it has today [casos confirmados na cidade]are from people tested, who went to the hospital”, said the biologist.
In the current stage of the research, 98.2% of the participants said they had taken at least the first dose of the vaccine against covid-19 and 91% said they had received two or three doses of the immunizer. The percentage of people who did not take any dose is 1.8%. For Reinach, the government’s mission now must be to lower the percentage even further and raise everyone to at least three doses.
Methodology
The methodology applied in the study divided the city into two segments, with higher and lower income districts, these strata represent, each, half of the adult population residing in the municipality.
Anti SARS-CoV-2 antibody levels (IgG and IgM) were measured using a chemiluminescence method, branded Abbott Architect, and a second electrochemiluminescence test, total Ig), from Roche. Neutralizing antibodies, in turn, were measured using the cPass SARS-CoV-2 Neutralization Antibody Kit test from Genzyme Inc.
