São Paulo, SP, and Rio de Janeiro, RG (Vulhabres) – For the first time in eight months, Brazil has seen cases of Covid-19 slow steadily. The country has been in a stable or accelerating phase since November last year, but this situation reversed as vaccination progressed.
The conclusion comes from Folha’s Covid accelerometer monitor. The platform measures the variability of newly infected people in the last 30 days, based on a statistical model developed by researchers Renato Vicente and Rodrigo Vega, of the University of the South Pacific.
The model compares seven-day moving averages over this period in municipalities with populations greater than 100,000, giving more weight to the most recent data. At each location, the pandemic is categorized as ‘initial’, ‘accelerated’, ‘stable’, ‘delayed’ or ‘low’.
Since April 7, the country has been at a stable level, there are still a large number of infected people, but the number of new cases per day does not change or grow strongly. But last Thursday (15), it entered a slowdown phase, which means infections are on a steady decline.
“The reduction is definitely related to vaccination, because it is proportional to the age groups that have been vaccinated,” says Paulo Lotofo, director of the Center for Clinical and Epidemiological Research at USP.
The decline in cases is occurring even as the movement of people across the country increases. Currently, the flow is almost equal to the period before the pandemic, according to data from Google that looks at movement in commerce and entertainment.
At the peak of infections, on June 22 this year, Brazil recorded a moving average of 79,000 new cases per day. On Thursday, when it entered the sluggish level, the number was 42 thousand. The same happened with deaths, which fell from 3,112 at the peak, on April 11, to 1,243 on Thursday (15).
In recent weeks, the states that switched from stable to lagging were Bahia, Mato Grosso do Sul, Paraíba, Rio de Janeiro, Rio Grande do Norte, Rondonia, Rio Grande do Sul, Tocantins and the Federal District, which contributed to the improvement of the national ranking.
Sao Paulo, the country’s most populous state, remains stable, but has recorded a decline in the number of cases in recent days and is on its way to entering a slowdown. No unit in the union has the epidemic on an accelerating level.
From the start, vaccines were made to reduce deaths and hospitalizations. “Now we see that it has an effect even on transmission,” says Lotofo, referring to the results of a study by the Putantan Institute in Serrana, in the interior of São Paulo, published in May.
Immunizing nearly all adults with two doses of Coronavac reduced symptomatic cases by 80% in the city. There has even been a decrease in infections among unvaccinated children and adolescents, while neighboring cities, such as Ribeirão Preto, have registered a rise.
Outside of Brazil, surveys point in the same direction. Last month, a survey published in the scientific journal Nature reported a reduction of over 60% in transmission after the first dose and 80% after the second dose among 385,000 UK residents who received vaccines from AstraZeneca and Pfizer.
In another study, a British government agency estimated that vaccination prevented at least 8 million infections in that country, which has a population of 65 million. However, the vaccine does not guarantee that a person will not contract or transmit the disease, which is why it is necessary to continue to wear a mask and to practice social distancing.
What is not yet clear is the effect of the delta variable, which was initially discovered in India and is already circulated in Brazil. In addition, there is concern about the possibility of other variants emerging, as happened with the strain identified in Manaus earlier this year.
“The fear now is the variables and that feeling that it’s gone. The numbers are dropping, but we’re still at a worse level than it was in 2020. If people relax and managers encourage events to show their transgression, they can increase again, says epidemiologist Diego Xavier, of Vuecruz. .
In the United States, which already has 59% of the adult population fully vaccinated, the number of new cases has more than doubled in the last 14 days — deaths grew timidly, at 9%. The delta variant will be prevalent there and has mainly reached people who have not yet been vaccinated.
According to Xavier, something similar is to be expected here. “You can already see the difference in the curves of places that have not adhered to the vaccine in the United States, with localized outbreaks. Hopefully the same will happen in Brazil, with more cases only in cities that do not have a second dose of coverage, for example, as Says.
Vaccination began in Brazil six months ago and reached only 26% of the adult population one month before the peak cases, taking into account those who were vaccinated with only a single dose or a single dose. The percentage doubled to 56% this week.
“We cannot pass up this opportunity again to look at the most vaccinated countries and take action before things go wrong, as we have done the entire pandemic,” the researcher warns.