Question: Why do different viruses attack different parts of the body?

Lucy McGowan answered on 16 Jun 2020:

All any virus needs is the space and genetic machinery (inside a cell) to make copies of itself and get passed along to the next human. Imagine if everyone in the UK tried to live in London. There would not be enough houses for everyone to live in, not enough food to eat, not enough jobs for everybody or enough schools for children. It makes more sense to spread out across the UK, right? It’s a bit like this for viruses in the body too! If every virus in the world tried to attack the same type of cell in the same body part, there would be too much competition. It makes more sense for different types of viruses to evolve different survival strategies. This increases their chance of reproducing and being passed along to another person. Now there are lots and lots of viruses that attack the lungs and guts, for example. This is because the mouth is a big opening between the outside world and the lungs and guts, so it’s easy for viruses to get in this way. You can imagine the lungs and guts to be like big cities in the UK, like London, Manchester, Birmingham etc; in these cities, there’s lots of jobs and a fast train in, but theres also a lot of competition for those jobs and seats on the train! Only the fittest can survive! That’s one of the reasons there’s a huge number of viruses which infect these parts of the body and why they change and adapt so quickly!