Invited Speaker Asia-Pacific Vaccine and Immunotherapy Congress 2023

The function and specificity of T cells in asymptomatic SARS-CoV-2 infection (#10)

Antonio Bertoletti 1
  1. Duke - NUS, Singapore

SARS-CoV-2 infection causes disease of different severity. We studied SARS-CoV-2-specific humoral and cellular immune responses in individuals from Kenya who never reported any symptom of respiratory infection and who were not knowingly in contact with COVID-19 patients. Among participants we detected anti-spike antibodies in 41.0% and T cell responses against ≥2 SARS-CoV-2 proteins in 82.5%, which implies that serosurveys underestimate SARS-CoV-2 prevalence in settings where asymptomatic infections prevail. Distinct from SARS-CoV-2 specific T cells detected in European and Asian COVID-19 convalescents, strong T cell immunogenicity was observed against viral accessory proteins in these asymptomatic Africans, as well as a higher IL-10/IFN-γ ratio cytokine profile. These data show that specificity and function of T cells differ in individuals with asymptomatic SARS-CoV-2 infection. The possibility that environmental factors can modulate pro-inflammatory responses and the implications about vaccine design will be discussed.