On Sept. 16, 2020, a study by researchers at La Jolla Institute for Immunology published in the Cell, confirmed that a multi-layered, virus-specific immune response is important for controlling the virus during the acute phase of the infection and reducing COVID-19 disease severity, with the bulk of the evidence pointing to a much bigger role for T cells than antibodies.

A weak or uncoordinated immune response, on the other hand, predicted a poor disease outcome. The findings suggest that vaccine candidates should aim to elicit a broad immune response that include antibodies, helper and killer T cells to ensure protective immunity.