Cross-reactive memory T cells abort SARS-CoV-2 infection

A study in health-care workers showed that some people, despite likely exposure to SARS-CoV-2, never develop PCR or antibody positivity. Swadling et al. hypothesized that pre-existing cross-reactive memory T cells, as described in pre-pandemic samples, may lead to abortive seronegative infections in these individuals. Indeed, they found T cell and innate transcript evidence for abortive infections. They also showed that these individuals frequently had memory T cells directed at the early transcribed replication transcription complex, which has high sequence conservation between human seasonal coronaviruses and SARS-CoV-2. Boosting such T cells with vaccines may allow for pan-reactivity against endemic and emerging coronaviruses.