New data suggest that children are less susceptible to severe COVID-19 because they have a stronger innate immune response than adults.
memory T cells
Some have suggested that pre-existing cross-reactive memory T cells in people with no prior exposure to SARS-CoV-2 may have a protective effect. However, recent findings indicate that this may not be the case.
On episode #254 of the science show This Week in Virology, Vincent, Dickson, Alan, and Kathy review clearance of simian immunodeficiency virus infection from macaques by immunization with SIV proteins encoded in a rhesus cytomegalovirus vector. You can find TWiV #254 at www.microbe.tv/twiv.