Specialised travel-medicine clinics are your best source of information; they stock all available vaccines and will be able to give specific recommendations for you and your trip. The doctors will take into account factors such as past vaccination history, the length of your trip, activities you may be undertaking, and underlying medical conditions, such as pregnancy.

Most vaccines don't produce immunity until at least two weeks after they're given, so visit a doctor four to eight weeks before departure. Ask your doctor for an International Certificate of Vaccination (otherwise known as the yellow booklet), which will list all the vaccinations you've received. In the US, the yellow booklet is no longer issued, but it is highly unlikely the Vietnam authorities will ask for proof of vaccinations (unless you have recently been in a yellow-fever affected country).

For info on current immunisation recommendations for Vietnam, contact the international team of doctors at the Family Medical Practice (www.dociorkot.com) in Hanoi  and HCMC. They can provide the latest information on vaccinations, malaria and dengue-fever status, and offer general medical advice regarding Vietnam.