COVID-19 P1 variant may be more transmissible, infectiousThe P1 variant that caused a second wave of COVID-19 infections in Manaus, Brazil, is more transmissible and from 25% to 61% of previously infected people may be susceptible to reinfection, according to a preprint, non–peer-reviewed study from researchers at the University of Sao Paulo, Imperial College London, and the University of Oxford.Despite fall 2020 serosurveys suggesting that Manaus' population had almost reached herd immunity for COVID-19 and had an attack rate above 67%, another COVID-19 surge hit the city late in the year.
For the new study, researchers examined 184 viral genomic samples collected from residents in November and December 2020 and found that the dominant