Has Common Cold Been a Shield Against COVID-19?

T-cell responses to SARS-CoV-2 have been discovered in non-infected humans, suggesting cross-reactive immune memory via previous exposure to human coronaviruses (HCoV) which induces common cold. This indicates that “immunity” exists in populations at higher rates than estimated previously. The graphic below summarizes the inferences from serological studies carried out globally.

However, with a limited ability to quantify HCoV CD4+ and CD8+ T-cell responses to SARS-CoV-2 infections, the configuration of pandemic prevention strategies based on COVID-19 pathogenesis is difficult. As an alternative strategy, it is important to merge the existing resources, including medical and contact-tracing databases, which are generated by relevant public health agencies. Incorporating data both from symptomatic and asymptomatic cases within SARS-CoV-2 repositories and surveillance systems might…