Alliance for Pandemic Preparedness

June 22, 2020

Clinical and Immunological Assessment of Asymptomatic SARS-CoV-2 Infections

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  • There was a longer duration of viral shedding among a group of 37 asymptomatic patients with SARS-CoV-2 infection in the Wanzhou District, China, compared to a paired symptomatic group (HR 1.69, 95%CI 1.06, 2.70). 
  • Asymptomatic individuals had significantly lower virus-specific IgG levels (median 3.4, IQR 1.6-10.7 vs. 20.5, 5.8-38.2; p = 0.005) in the acute phase of infection. Asymptomatic individuals were more likely to have a reduction in neutralizing antibody levels (81% vs. 62%) and to become seronegative (40% vs. 13%) during the early convalescent phase. 
  • These data suggest that asymptomatic individuals may mount a weaker immune response to SARS-CoV-2 infection, which could have implications for immunity strategies and serological surveys. 

Long et al. (June 18, 2020). Clinical and Immunological Assessment of Asymptomatic SARS-CoV-2 Infections. Nature Medicine. https://doi.org/10.1038/s41591-020-0965-6