advertisement

The flu virus

Cold or flu?

Both are common in winter and caused by viruses. We often confuse the one with the other. But there is a huge difference between a cold and influenza: influenza may kill you.

How flu viruses change

The genetic make-up of influenza viruses A and B can change in two ways: a slight change known as antigenic drift and dramatic changes known as antigenic shift.

Worldwide flu surveillance

The World Health Organisation (WHO) keeps constant surveillance of the human influenza strains circulating around the world.

load more articles
advertisement