Your questions answered

摘要

Why do people without underlying health conditions get seriously ill from covid-19? Some people get seriously ill from covid-19 without any known risk factors. Genetic make-up is likely to play a role - we have long known that having a parent who died young from an infectious disease puts you at a sixfold greater risk of doing so yourself. The genes that make a difference are probably involved in the immune system. Are you protected if you have been infected by a different coronavirus? There are at least four other kinds of coronavirus that cause coughs and colds, but we don't know if having encountered one of these puts you in a worse or better position. Often, if your immune system makes antibodies against one microbe, it gets a head start for fighting a related one later on. But this doesn't always apply. There is evidence that encountering a virus can sometimes lead to worse symptoms in subsequent infections involving the same virus or a similar one.