Model-based estimation of transmissibility and reinfection of SARS-CoV-2 P.1 variant

SARS-CoV-2, the virus that causes COVID-19, can mutate into variants which might have different characteristics such as increased ability to spread. The P.1 variant, also known as Gamma, was first identified in Manaus, Brazil. Here, we use mathematical and statistical methods to model the spread of P.1 in Manaus and to determine the potential for people getting re-infected with P.1, comparing it to previous circulating variants in the region. We estimate that P.1 spreads 2.6 times more easily than these other variants and that nearly a third of cases over the period studied were reinfections with P.1. These findings help us to understand whether P.1 is likely to be more difficult to control than other variants and what sort of measures might be needed.