Infants have a high proportion of naive T cells and as they move towards adulthood, they get exposed to to more viruses, the naive T cells are replaced by memory T cells
People who have been infected with COVID-19 and vaccinated against it are more likely to avoid serious illness than those who were only previously infected, a new study says.
SINGAPORE, Aug 25 To prepare for the next wave of Covid-19 cases, which is likely to be driven by re-infections, Singapore is setting up transition care facilities, preparing.