Brazil has already seen the emergence of two especially virulent variants of Covid-19 and scientists fear the giant South American nation will become a Petri dish for more variants if contagion continues at the current elevated rate.
The virus has claimed 373,000 lives in Brazil, second only to the United States, and was only recently overtaken by India - with a population that is five times larger - in the number of cases.
Confirmed infections in Brazil already stand at 13.9 million and are increasing by an average of 65,000 per day.
Latin America's leading medical research institution, the Rio de Janeiro-based Oswaldo Cruz Foundation (Fiocruz), says that 92 of the more than 900 Covid-19 variants identified worldwide have been detected in Brazil.
Two of those variants, P.1 and P.2, originated in Brazil, and scientists are currently investigating what could be a third Brazilian variant.
Health authorities suspect that P.1, spotted last year in the Amazonian city of Manaus, has been the main driver of Brazil's spike in infections and deaths.
P.1 is 2.4 times more contagious than the original strain of the virus and may be impervious to the antibodies generated by the immune system of people who survived a previous Covid-19 infection, according to a study published in Science magazine.
Present in 52 countries, P.1 is one of three versions of the virus classified by the World Health Organization as a "variant of concern." The others are B.1.1.7, first spotted in the United Kingdom, and B.1.351, which arose in South Africa.
The P.2 variety, P.2, first isolated in Rio de Janeiro, is listed as a "variant of interest."
P.3 emerged in the Philippines and Brazilian scientists are now working to determine if another variant - provisionally known as P. 4, is circulating in and around the southeastern city of Belo Horizonte.
"In two of 85 samples we found a combination of variations that does not match anything described previously," the coordinator of the team working in Belo Horizonte, Renan Pedra, told Efe.
Pedra, a professor at the Federal University of Minas Gerais, said that more work will be needed to establish whether the genetic variation has an impact on transmissibility of the virus or the severity of illness.
For the moment, the Brazilian health system is on the verge of being overwhelmed by the P.1 variant, which is thought to account for more than 90 percent of new cases in the country, according to Jose Eduardo Levi, a researcher with the University of Sao Paulo's Institute of Tropical Medicine.
The dominance of P.1 means that Brazil faces "an epidemiological scenario different from the rest of the world," he said.
"The fear we have is that P.1 develops vaccine-resistant mutations," Levi said, adding that the combination of the high rate of infection and the slow pace of vaccination could provide the conditions for a such a development.
Most of the 33.5 million Brazilians to be vaccinated so far have had only the first of the two required doses.
"The outlook is very bad and we're afraid of what will happen with vaccinated people who become infected with P.1," Levi said. EFE cms/dr