Artikel i Lancet om Manaus Brasilien. De går igenom 4 möjliga förklaringar till andra vågen.
tredje alternativet är inte så trevligt. Verkar finnas två Brasilianska mutationer. P1 och P2
"Third, SARS-CoV-2 lineages might evade immunity generated in response to previous infection.15 Three recently detected SARS-CoV-2 lineages (B.1.1.7, B.1.351, and P.1), are unusually divergent and each possesses a unique constellation of mutations of potential biological importance.16, 17, 18 Of these, two are circulating in Brazil (B.1.1.7 and P.1) and one (P.1) was detected in Manaus on Jan 12, 2021.16 One case of SARS-CoV-2 reinfection has been associated with the P.1 lineage in Manaus19 that accrued ten unique spike protein mutations, including E484K and N501K.16 Moreover, the newly classified P.2 lineage (sublineage of B.1.128 that independently accrued the spike E484K mutation) has now been detected in several locations in Brazil, including Manaus.20 P.2 variants with the E484K mutation have been detected in two people who have been reinfected with SARS-CoV-2 in Brazil,21, 22 and there is in-vitro evidence that the presence of the E484K mutation reduces neutralisation by polyclonal antibodies in convalescent sera.15"
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)00183-5/fulltext