Although there is much attention being directed toward SARS-CoV-2, the coronavirus at the center of the global pandemic, there are multiple coronaviruses that infect humans.
These seasonal coronavirus infections occur frequently and typically result in a mild, common cold-like illness. The presence of these coronavirus infections in the population has led to the hypothesis that immune cross-reactivity among these related viruses could occur, and potentially offer some protection to SARS-CoV-2. Now, a group of scientists has detected preexisting antibody-driven immunity against SARS-CoV-2 in a small proportion of individuals who were uninfected at the time of sampling.
This work is published in Science in the paper, “Preexisting and de novo humoral immunity to SARS-CoV-2 in humans.”
The four coronaviruses that result in a common cold-like infection when infecting humans are 229E (alpha coronavirus), NL63 (alpha coronavirus), OC43 (beta coronavirus), and HKU1 (beta coronavirus). The other three coronaviruses known to infect humans cause far more serious infections. They are MERS-CoV (the beta coronavirus that causes Middle East Respiratory Syndrome, or MERS), SARS-CoV (the beta coronavirus that causes SARS), and SARS-CoV-2, the novel coronavirus that causes COVID-19.
People around the world commonly get infected with human coronaviruses 229E, NL63, OC43, and HKU1.
The London-based group of researchers found that 16 out of 302 adults (5.3%) harbored IgG antibodies that were likely generated during previous seasonal “common cold” coronavirus infections, and which cross-reacted with subunit S2 of the SARS-CoV-2 spike protein complex.Original Source