Disease & Immunization Information Ideally, immunizations should be given at least one month in advance of your trip. The only immunizations required by law in some countries are for cholera or yellow fever. You should also make sure that your polio and tetanus-diphtheria booster immunizations are still effective. Travelers to developing countries with poor sanitation should also consider typhoid and hepatitis vaccines. Children should have all of their basic immunizations series up to date. If there is a risk of malaria in a country you are planning to visit, you will need anti-malaria pills and these need to be taken before, during and after your trip. On the left we have listed the major diseases you should be aware of and if you click on the button you will get an explanation of the disease, precautions and related immunizations.