April 30, 2021 -- The coronavirus variant first detected in Brazil appears to be much more transmissible than other versions of the virus, a new study says.
The study, first published in Science, also said the variant called P.1 might be able to evade immunity that people gained after previously being infected with coronavirus.
Brazil has struggled desperately with the COVID pandemic, reporting 14.5 million confirmed cases (third most in the world) and almost 399,000 COVID-related deaths (second most in the world).
Manaus, the capital city of Amazonas, has been especially hard hit.
In an article about the study, Science Daily noted that about 75% of the people in Manaus were infected by the first COVID wave in mid-2020. Some experts speculated the city might have reached herd immunity.
But a second wave of infections slammed Manaus in late 2020, with P.1 being the dominant strain.
“Our epidemiological model indicates that P.1 is likely to be more transmissible than previous strains of coronavirus and likely to be able to evade immunity gained from infection with other strains,” a corresponding author to the new study, Samir Bhatt, a researcher at the Department of Public Health at University of Copenhagen, said in Science Daily.
The researchers found P.1 acquired 17 mutations, including three mutations in the spike protein. The P.1 strain is 1.7 and 2.4 times more transmissible than other coronavirus strains and can avoid 10% to 46% of the immunity that people gain from being infected with other strains.
Researchers also determined people in Manaus were 1.2 to 1.9 times as likely to die from a P.1 infection than infection with other strains.
But the study noted that “the recent epidemic in Manaus has strained the city’s healthcare system leading to inadequate access to medical care. We therefore cannot determine whether the estimated increase in relative mortality risk is due to P.1 infection, stresses on the Manaus healthcare system, or both.”
The P.1 variant has spread around the world since being discovered in Brazil. In the United States, 497 cases have been reported in 31 states, the CDC said.