Asymptomatic Reinfection in 2 Healthcare Workers From India With Genetically Distinct Severe Acute Respiratory Syndrome Coronavirus 2

Understanding protection from SARS-CoV-2 by studying reinfection

“…Notably, the viral strain was from a clade different from that of the initially infecting strain, and the second strain resembled the viruses circulating in the time frame and region in which the person traveled -a story much like the first case report of HIV reinfection. In the other recently published cases, an interval of about two to four months between the detection of SARS-CoV-2 viral RNA and the sequence differences between the viruses support the proposal of reinfection 2,3 . The fact that two cases were healthcare workers and were potentially continually exposed to the virus adds to the likelihood that these were indeed cases of reinfection 2 .…”

“…One common benchmark for measuring vaccine efficiency is eliciting neutralizing antibody levels similar to those elicited by natural infection, on the basis of the assumption that infection induces responses that protect against reinfection. In the case of SARS-CoV-2, recent reports of reinfection, as indicated by viral sequence differences, clinical data and data on potential exposure, have raised critical questions about whether and how well a first infection protects against reinfection [1][2][3] .…”

COVID-19: Rethinking the Lockdown Groupthink

“…The seven published case reports of re-infection, four with symptoms [one requiring hospitalization, and one death in an immunocompromised 89 year old with few details reported], when 10% of the world population has likely been infected over the past 10 months cannot yet provide evidence that severe reinfection and contagion is at all common. [232][233][234][235][236][237] Regarding Manaus, the high seroprevalence likely reflected the special situation of a relatively homogeneous cohort of people in overcrowded low socioeconomic urban situations, with reliance on crowded long riverboat travel; now there seems to be a different demographic cohort of young wealthy individuals being exposed. [238][239][240] In addition, the peak seroprevalence in blood donors in Manaus was 51.8% in June, while another study of household seroprevalence in Manaus on May 14-21 found this to be 12.7% [the respective numbers for Sao Paulo were closer, at 6.9% and 3.3% in the two serosurveys].…”

Long-term persistence of neutralizing memory B cells in SARS-CoV-2

“…The very few validated cases of reinfection of SARS-CoV-2 have also been associated with mild or asymptomatic infection. 20 Encouragingly our data shows that despite the declining NAb titres, in the great majority of participants that seroconverted, memory B cells against RBD were maintained and even increased in numbers at four to six months following infection in 12 out of 13 participants. This finding was similar to three other studies that also reported the maintenance and expansion of the RBD-specific IgG memory repertoire 16,17,21 .…”