Vaccination against COVID-19 saved the lives of 54,000 to 63,000 elderly people during the first eight months of 2021. It also prevented 158,000 to 178,000 hospitalizations of people aged 60 or over in Brazilian hospitals in the same period. The numbers, published in the scientific journal The Lancet Regional Health Americas, could be even better. This is because they are part of an analysis considered “conservative” by the authors of the study, members of the COVID-19 BR Observatory. What is certain, they say, is that the result of the work demonstrates the positive impact of mass immunization in the country.
“The fact that vaccines have made a difference is undeniable”, says researcher Leonardo Souto Ferreira, first author of the article and researcher at the Institute of Theoretical Physics at Universidade Estadual Paulista, to Jornal da Unesp. In addition to Unesp, the Oswaldo Cruz Foundation (Fiocruz), the State University of Campinas (Unicamp), the Federal University of ABC (UFABC) and the University of São Paulo (USP) are part of the observatory.
The group analyzed data referring to the period between January and August 2021, the first months of vaccine application in the country, and chose the elderly because they were the first to complete the vaccination schedule, according to the adopted schedule. By combining the death and hospitalization curves in this interval, the scientists concluded that the correlation between the two phenomena and immunization was evident: the greater the vaccination coverage, the smaller the impact of COVID-19 among those aged 60 years or older. The data showed, for example, a reduction of approximately 35% in hospitalizations of the elderly in the period considered.
According to Leonardo Ferreira, the effect must have been repeated among younger individuals. “Our model assumes that the behavior of the epidemic in the different age groups is the same. Not in the sense that they have the same number of cases, but that they have the same behavior of rising and falling, more or less, in the same moment,” he explains. “The number of serious cases in the elderly began to fall, while the number of hospitalizations in younger people continued to rise. This behavior is due to vaccination in that population”, he completes.
gamma variant
The group of scientists also estimated how many lives and hospitalizations could have been avoided if the country had adopted an accelerated pace of vaccination since the beginning of the campaign, which started on January 18, 2021. For the authors, immunization was gradually gaining speed. Between February and March of that year, around 250,000 doses were applied per day. In June alone, the level of 1 million was reached.
Had this pace been adopted eight weeks after the beginning of the campaign, in mid-March, the number of elderly deaths could have been 40% to 50% lower than that observed at the peak of the gamma variant epidemic. In this way, another 47,000 deaths and an additional 104,000 hospitalizations of people over 60 could have been avoided, indicates the Brazilian study.
“Although we could not prevent the emergence of the gamma variant, as it appeared in November and vaccines were made available in January, a rapid vaccination could considerably reduce the peak of hospitalizations and deaths, especially among the elderly and especially in states where the gamma it took a while to arrive”, assesses Flávia Maria Darcie Marquitti, a researcher at the Gleb Wataghin Institute of Physics and the Institute of Biology, both at Unicamp.
Children
The authors also consider that, in mid-2021, the immunization of the population, already at an accelerated pace, played a “decisive role” in preventing the emergence of a new serious wave of COVID-19 due to the appearance of the delta variant, which spread across the country and became dominant. “When the delta arrived, it found it more difficult to circulate”, explains Marcelo Gomes, co-author of the study and researcher in Public Health at Fiocruz.
For the Fiocruz scientist, the observed results indicate that the strategy can be efficient for vaccinating children against COVID-19. “Children’s vaccination has been slow because a series of unfounded questions were raised about the safety of the vaccine, which ended up generating what we call vaccine hesitancy, that is, part of the population was in doubt regarding the safety and effectiveness of the vaccine “, it says.
Financial impact
The study also estimated how much was saved with the reduction in the number of hospitalizations. Considering that each hospitalized person had, during the pandemic, an average cost of US$ 12,000, avoiding 158,000 to 178,000 hospitalizations represented an estimated saving in a range of values from R$ 1.9 billion to R$ 2.1 billion to the Brazilian health system.