What a vaccine actually does in your body

A short, useful read for the UpdateSee community.

A vaccine shows the immune system a harmless piece or copy of a germ so that it can prepare before the real thing arrives. The body produces antibodies and memory cells, which take a couple of weeks to form. If the actual virus or bacterium turns up later, those memory cells recognise it immediately and the response is fast enough to prevent serious illness.

A vaccine shows the immune system a harmless piece or copy of a germ so that it can prepare before the real thing arrives.

The tiredness or sore arm that follows some doses is the immune system doing its work, not the disease. Protection fades at different rates for different infections, which is why some vaccines need boosters and others last for life. Reliable information comes from national health services and the World Health Organization rather than from anonymous posts.