HOW WE SOLVED COVID

Experts the world over came together to create a vaccine in record speed. What does that mean for other health concerns?

- Drew Turney

The scope and seriousness of the COVID-19 pandemic was made real to many in March 2020 when the UK went into lockdown, confining us all to our homes, and preventing social contact with friends and family. Fast forward a year or so and a vaccine has been developed, travel restrictions eased and reunions made possible for our nearest and dearest. But how did we do that so fast, when we've been living with HIV for almost half a century, battled cholera for 200 years and evolved alongside the common cold for millennia?

The answer's complicated. As Dr Kylie Quinn of the School of Health and Biomedical Sciences at Melbourne's RMIT University explains, the trick to vaccines is to look for people who've been infected and recovered. If you can see that in the population, you can be reasonably confident you can replicate it with a vaccine.

Most people with COVID-19 have some degree of immunity after they recover, just like most of us do against chicken pox. But this isn't true for all diseases—you can catch malaria repeatedly, and HIV attacks the very immune system designed to protect you.

Another complicating factor is that viruses—like every other life form—mutate and evolve, and some are better at it than others. The British Medical Bulletin published research in 2001 in which the genetic variation in a single patient HIV case was equal to those found in common cold cases across North America for an entire year.