Understanding the immunology behind COVID-19

This week’s expert:
Professor Andrew Lloyd, Infectious Diseases Physician at Prince of Wales Hospital, Sydney and Head of the Viral Immunology Systems Program, Kirby Institute.

Drawn from an interview with Prof Lloyd by Dr Harry Nespolon on the Healthed podcast Going Viral.

• COVID-19 is an RNA virus from the coronavirus family and a relative to a number of viruses that cause cold-like symptoms as well as the viruses the caused SARS and MERS. In structure it is 80% identical to the virus that caused SARS.

• To understand the morbidity related to COVID-19, one has to understand the host response to the viral infection which involves two key elements – the innate response, which is the body’s first response on recognising it has been infected by a pathogen – any pathogen – and then there is the development of adaptive immunity. This is the body’s attempt to combat infection by this specific pathogen, and commonly involves a humoral response where the B cells produce antibodies which can recognise this infecting virus and inhibit it from entering cells or replicating once inside the cell, as well as T cell immunity, where circulating lymphocytes are mobilised to either kill or protect against the virus.