Between November and January in Manaus, Brazil, the frequency of COVID-19 cases involving the P.1 coronavirus variant increased from 0% to 73%, and the number of infections there quadrupled compared to what the city experienced in the first wave of the pandemic, according to a report posted on medRxiv ahead of peer review. The greater infectiousness of the P.1 variant likely contributed to that, the report suggests. Based on national health surveillance data, the authors estimate that the P.1 variant is roughly 2.5 times more transmissible than previous variants circulating in Manaus. The spread of P.1 occurred despite the fact that 68% of the city's population had already been infected by the original strain of the coronavirus, the researchers noted. In their analysis, the risk of reinfection with P.1 was low. The ability of the variant to cause severe disease, or its pathogenicity, is still unclear. "The P.1 variant has already been detected in at least 25 countries," the authors said. "This calls for urgent ... studies of the P.1 variant, since greater transmissibility and pathogenicity can drive even well-prepared health systems to collapse." —Reuters Staff Source
