Developing a vaccine is difficult at the best of times, but rarely have we been in a situation where basic knowledge about a virus has to be acquired so directly alongside the race to eradicate it. To understand how difficult this task is, we must appreciate the complexity of how our immune system responds to an infection.
The part of the immune response that can target germs precisely and provide long-term protection is called the adaptive immune response. Two types of white blood cell are important in this: T cells and B cells. These cells work together to orchestrate a targeted immune response. But the way they recognise and deal with germs is different.