This rapid research brief analyses the factors that influence the risk of infection, the risk of severe disease requiring hospitalisation or intensive care unit (ICU) admission, and the risk of death.

Main findings:

• There is little evidence that biological differences, including age, sex and comorbidity, influence the risk of acquiring the coronavirus infection.
• Age is the leading determinant of severe disease and death among people with COVID-19. The risk associated with age increases rapidly from the age of 40 years.
• Compared to females, males with COVID-19 are more likely to be hospitalised, more likely to be admitted to an ICU and more likely to die.
• Among people with COVID-19, many medical co-morbidities, such as heart disease and chronic obstructive pulmonary disease, increase the risk of hospitalisation, ICU admission and death. However, some co-morbidities, such as asthma, probably do not increase risks.