Swiftly waning Covid-19 immunity poses vaccination challenge

CORONAVIRUS | Emerging evidence that the body's immune defence against Covid-19 may be short-lived makes it even harder for vaccine developers to come up with shots fully able to protect people in future waves of infection, scientists said on Tuesday.

Preliminary studies in China, Germany, Britain and elsewhere have found that patients infected with the novel coronavirus make protective antibodies as part of their immune system's defences, but these appear to last only a few months...