A case series of SARS-CoV-2 reinfections caused by the variant of concern Gamma in Brazil

Abstract

SummaryThe rapid spread of the SARS-CoV-2 Variant of Concern (VOC) Gamma during late 2020 and early 2021 in Brazilian settings with high seroprevalence raised some concern about the potential role of reinfections in driving the epidemic. Very few cases of reinfection associated with the VOC Gamma, however, have been reported. Here we describe 25 cases of SARS-CoV-2 reinfection confirmed by real-time RT-PCR twice within months apart in Brazil. SARS-CoV-2 genomic analysis confirmed that individuals were primo-infected between March and December 2020 with distinct viral lineages, including B.1.1, B.1.1.28, B.1.1.33, B.1.195 and P.2, and then reinfected with the VOC Gamma between 3 to 12 months after primo-infection. The overall mean cycle threshold (Ct) value of the first (25.7) and second (24.5) episodes were roughly similar for the whole group and 14 individuals displayed mean Ct values < 25.0 at reinfection. Sera of 14 patients tested by plaque reduction neutralization test after reinfection displayed detectable neutralizing antibodies against Gamma and other SARS-CoV-2 variants (B.1.33, B.1.1.28 and Delta). All individuals have milder or no symptoms after reinfection and none required hospitalization. The present study demonstrates that the VOC Gamma was associated with reinfections during the second Brazilian epidemic wave in 2021 and raised concern about the potential infectiousness of reinfected subjects. Although individuals here analyzed failed to mount a long-term sterilizing immunity, they developed a high anti-Gamma neutralizing antibody response after reinfection that may provide some protection against severe disease.

Persistence of SARS-CoV-2 neutralizing antibodies longer than 13 months in naturally infected, captive white-tailed deer ( Odocoileus virginianus ), Texas

“…Experimentally, infected cats produced neutralizing antibodies sufficient to prevent reinfection following a second viral challenge [ 14 ]. Further, reinfections caused by different variants have been widely reported in humans [ 15 ].…”

Persistence of SARS-CoV-2 neutralizing antibodies longer than 13 months in naturally-infected, captive white-tailed deer (Odocoileus virginianus), Texas

“…Experimentally, infected cats produced neutralizing antibodies sufficient to prevent reinfection following a second viral challenge [12]. Further, reinfections caused by different variants have been widely reported in humans [13].…”

Clinical and epidemiological aspects of Delta and Gamma SARS-CoV-2 variant of concern from the western Brazilian Amazon

“…The Gamma VOC was responsible for rapidly spreading waves of infections in Brazil, making it the most prevalent variant from January through August 2021, 18 , 19 possibly justified by its high transmissibility and partial immune evasion, as shown by reinfection cases. 20 However, this scenario changed after the introduction of the Delta VOC with the first confirmed case in RO on August 3, 2021, leading to a gradual increase in cases as described in this study. The incidence of SARS-CoV-2 in the state decreased between June and October, from 237.8 to 22.8 cases per 100,000 inhabitants; however, in November and December, there was a significant increase where the incidence rates recorded were 80.7 and 126.7, respectively, with the highest numbers in relation to the other states in the northern region of the country.…”