October 16, 2020

Cellular Immunity in COVID-19 Convalescents with PCR-Confirmed Infection but with Undetectable SARS-CoV-2–Specific IgG

Category: Article Summary

Topic: Vaccines and Immunity

Keywords (Tags): immunity

Immunity to SARS-CoV-2 infection may be mediated through T-cells, even among those with undetectable levels of antibodies against the virus. A study of immune responses against severe SARS-CoV-2 among a group of convalescent, potential blood donors in Germany found T-cell immunity against SARS-CoV-2 in 78% of volunteers who had a PCR-confirmed SARS-CoV-2 infection but had undetectable antibodies. The study analyzed participants who had strong antibody responses as positive controls and asymptomatic individuals with no household contact with infected individuals as negative controls. A similar frequency (80%) of T-cell immunity was observed in donors with strong antibody responses, and immunity was not detected in negative controls. 

Schwarzkopf et al. (Oct 15, 2020). Cellular Immunity in COVID-19 Convalescents with PCR-Confirmed Infection but with Undetectable SARS-CoV-2–Specific IgG. Emerging Infectious Disease Journal. https://wwwnc.cdc.gov/eid/article/27/1/20-3772_article