Researchers have found evidence suggesting that the P.1 COVID variant could be twice as transmissible as prior strains. The findings were published in the Journal Science.
The P.1 SARS-CoV-2 variant was first detected in four travellers from Brazil during a routine screening at Haneda airport, Tokyo. Manaus, the capital of the state of Amazonas in Brazil was the origin of the variant. According to preliminary investigations, the virus emerged late in 2020, beginning to spread in November and then quickly became the dominant strain. This prompted many to believe that it could reinfect those infected with the initial strain.
Some 70% of the residents in the city were believed to have been infected during the initial infection period. After variant infections rose in Manaus, the P.1 variant soon spread throughout Brazil, and then to other countries—thus far, it has been detected in at least 37 countries.
The researchers used molecular clock analysis to determine that the virus had 17 identifiable mutations and that three spike protein mutations (N501Y, E484K and K417T) allowed the virus to bind more effectively to host cells. These also may help in evading antibodies, and the researchers also found that P.1 can evade immunity granted by prior strains.
In simulations, P.1 was 1.7 to 2.4 times more transmissible than the prior virus baseline, but whether this was due to longer persistence in the body or increased viral load could not be determined. Additionally, it could not be established if it increased disease severity or raised mortality rates. Though people inffected with the variant were 1.2 to 1.9 times as likely to die, this could have been a result of the severe strain the overburdened healthcare systems were experiencing in the city.
More work is needed to find out whether the P.1 strain can infect those infected with prior strains or have been vaccinated, the researchers said.
Source: Medical Xpress
Journal information:Â Nuno R. Faria et al. Genomics and epidemiology of the P.1 SARS-CoV-2 lineage in Manaus, Brazil, Science (2021). DOI: 10.1126/science.abh2644
