Contributing to research themes:
Even in nonpandemic times, respiratory viruses account for a vast global burden of
disease. They remain a major cause of illness and death and they pose a perpetual
threat of breaking out into epidemics and pandemics. Many of these respiratory
viruses infect repeatedly and appear to induce only narrow transient immunity,
but the situation varies from one virus to another. In the absence of effective
specific treatments, understanding the role of immunity in protection, disease,
and resolution is of paramount importance. These problems have been brought
into sharp focus by the coronavirus disease 2019 (COVID-19) pandemic. Here, we
summarise what is now known about adaptive immunity to severe acute respiratory
syndrome coronavirus 2 (SARS-CoV-2) and draw comparisons with immunity to
other respiratory viruses, focusing on the longevity of protective responses.