What are Vaccines?

Vaccines are a kind of medicine that improve your body's immunity against a particular disease. Vaccines are usually not the 'real' disease - they're a dead, dummy form of the real thing. Vaccines fool your immune system into making protection against the real disease, should you ever encounter it while abroad. This means your immune system will be able to fight off the real disease when you're abroad without your ever knowing you had encountered it.

Most vaccines come in the form of a small injection into the upper arm (the top of the upper arm where the most muscle is found). The injection shouldn't hurt, as long as it's done really gently, using the smallest possible needle and while the arm is relaxed.

Nowadays, combined vaccines are available where it's possible to receive one shot that will cover several diseases at the same time (see table below).

Some vaccines involve one shot only (see table below) and work within 2 weeks. Vaccines that involve 2 or more shots (given over 2 or more visits) take a bit longer to work - typically 4 to 6 weeks.

Several types of vaccines (three or four) can be given at the same time if necessary.

Will vaccines produce side-effects? Possibly, but probably not. The most common side-effects occur a day or two later and include: heavy arm, some tenderness at the site of injection, mild flu-like symptoms.