Brazil has record Covid drop in major cities since the beginning of the pandemic

Four out of five cities with more than 100,000 inhabitants in Brazil had a reduction in new Covid-19 cases in October, the highest rate of the entire pandemic.

Data are from Covid’s acceleration monitor sheet, which measures the rate of growth of new coronavirus infections in large states and municipalities, which have more stable and reliable data than smaller ones.

On average, October had 260 cities per day in the deceleration stage, when the number of new cases is falling. This represents 80% of the 326 cities with more than 100,000 inhabitants.

The worst rate was in May 2020, when the daily average of cities with a reduction in cases reached three.

In turn, October 2021 had the lowest number of municipalities with an accelerated increase in cases — an average of 16 per day (5%). At this stage, according to the monitor’s classification, the rate of infections grows significantly and uncontrolled. The peak was in June of last year, with 287 (88% of large cities).

The monitor also has three other possible stages: stable (when the number of new cases is constant but considerable), reduced (when there are no or very few new cases) and initial (when cases start to appear, at the beginning of the epidemic ).

Among the 27 capitals, 21 spent the entire last month in the deceleration stage. This is the case of São Paulo, Salvador, Manaus, Recife, Rio de Janeiro and Porto Alegre, for example.

Boa Vista, Brasília, Florianópolis, Fortaleza, Teresina and Vitória had part of the days in a stable situation or with accelerated growth of cases, although most of the month was in deceleration or stability.

In the total of municipalities with more than 100 thousand inhabitants, 182 (56%) were in deceleration during every day of October.

Only one city, Valparaíso de Goiás (GO), spent the entire month with an accelerated increase in cases. For comparison purposes, in April this year there were 20.

October was also the month with the highest number of large cities without Covid deaths since May 2020. There were 22 (7%) and 43 (13%), respectively.

In the total of 5,570 Brazilian cities, 3,612 (65%) had no deaths last month. It is the highest percentage since May 2020 (72%).

Experts heard by sheet they see the drop in the number of cases with optimism and state that it is mainly due to the advance of vaccination and, more specifically, to a recent vaccination in the country.

“This is the great impact of a population with high vaccination coverage and recently vaccinated, as we now know that vaccines partially lose their protection over the months, although protection for severe cases, hospitalizations and deaths is longer lasting “, explains Renato Kfouri, pediatrician and director of SBim (Brazilian Society of Immunizations).

Despite having started the vaccination campaign against Covid about a month after countries like the United Kingdom and Germany, Brazil managed to advance and surpassed the mark of 70% of the population with at least one dose in the beginning of October.

Today, about 75% of the Brazilian population has received at least one dose of immunizing agents and 58% have already taken both doses or a single dose. In other countries, there is some difficulty in getting people who oppose vaccination to join the campaign.

In the US, where there is low adherence to vaccines in some states, vaccination coverage is not homogeneous, reaching around 40% of the fully vaccinated population in places like West Virginia and Wyoming.

“We have a coverage that is homogeneous, and that is also important”, adds Kfouri.

An upsurge in the pandemic is also observed in Europe, with some countries like the Netherlands enacting new lockdowns. The European continent accounted for more than half of the new Covid cases in the world at the end of October and saw a sudden rise in new infections and hospitalizations by Covid after the relaxation of protective measures.

“This is a problem and we must be attentive because, despite the favorable epidemiological moment, it is important not to loosen the measures”, emphasizes the epidemiologist and professor at the Faculty of Medicine of USP Paulo Lotufo.

Maintaining care, such as wearing masks, keeping people apart and preferably going to outdoor or well-ventilated spaces are measures that help to reduce the circulation of the virus.

“Vaccination plays a very important role in the slowdown of the pandemic in the country, but it alone is not our only weapon”, stresses Denise Garrett, epidemiologist and vice president of the Sabin Institute of Vaccines (USA).

“In Brazil, we still do not have a vaccine coverage rate sufficient for it to explain the complete slowdown of the pandemic by itself”, he says.

For specialists, almost two years after the start of the pandemic, one thing has already become clear: the movements of the disease came like waves, with the increase in cases at times of high susceptibility of populations or by a low number of people already immunized, or even for an escape of protection against new variants. Therefore, it is difficult to predict the future.

“We have seen that countries that have improved with vaccination and other control measures, when they relaxed, had problems again. Therefore, in this moment of transition, it is important to be as cautious as possible to maintain these levels [de novos casos] low,” says Garrett.

For Lotufo, “epidemiologically speaking”, it is difficult to say when the pandemic will end. “But I believe it is moving faster than we thought. We are near the end of the beginning of the pandemic, but not yet the beginning of the end.”

Covid’s acceleration monitor sheet is a statistical model developed by USP researchers Renato Vicente and Rodrigo Veiga. Based on the evolution of cases in each location (city, state, country), the parameter is a period of 30 days, with greater weight for the most recent period.

With this, the acceleration of the epidemic is measured, that is, the way in which the number of new cases increases or decreases. The numbers are updated daily (with each update, the oldest day in the 30-day series is removed from the calculation).

In the classification, the model considers the most present stage in the last seven days. Thus, there is greater stability in the classification presented daily, avoiding possible sudden changes caused by problems in the disclosure of data by the Health Departments.