Question: how do you cure viruses you have never seen before?

Ian Hands-Portman answered on 21 Mar 2014:

We can’t – or very rarely. We’re not very good at treating viruses – things like antibiotics are great against bacteria but useless against a virus like a cold.

There are some drugs available – tamiflu and relenza both attack an enzyme that the flu virus needs to leave a cell it’s infected. Nevirapine attacks an enzyme that HIV needs to copy its genes into a form our own cells can understand but all of these drugs just slow things down until our immune system can get the upper hand – or at least hold itself together in the case of HIV.

If a new virus appears the first thing we’d do is find out what it’s related to and try any drugs we have against that, we’d then be looking for a way to grow the virus in the lab and use that information to try to find a vaccine – that won’t cure anyone but can stop you getting the disease.

A vaccine can be as simple as just the virus treated with a chemical to kill it or fragments of broken virus, with polio we actually use a living virus that’s been weakened to stop it causing disease. Many of the new vaccines actually use artificially made particles called ‘virus like particles’ that just look like the virus to our immune system.