Travel Vaccine Information
Many of the diseases that the more developed countries have eliminated are still prevalent in other parts of the world.
Travellers to tropical countries as well as to many other regions will need to be vaccinated against these diseases. Examples include: yellow fever, hepatitis, typhoid fever, polio, diphtheria and many others.
When deciding which travel vaccines are required, each individual traveller should obtain information relating to the country or countries they intend to visit. (e.g. the tables of vaccine requirements in this site). It should be noted however, that even experts disagree on the detail and travellers may receive conflicting information.
Travellers should therefore assess their own risk by considering the nature of their trip; For example, a business traveller visiting only hygienic, air conditioned premises for a few days cannot be compared to someone travelling extensively to rural areas of the same country where health risks are considerably higher and access to medical facilities is limited or poorly developed.
Despite their success in preventing disease, vaccines are not 100% effective all of the time. The vaccinated traveller should never assume that there is no risk of catching the disease against which they have been vaccinated. All the usual precautions should be followed carefully as these can be as important in preventing the illness as the vaccine itself.
Vaccines, how do they work?
When the body is exposed to foreign organisms, such as bacteria and viruses, the immune system produces antibodies against them. Antibodies help the body recognise and kill the foreign organisms. They then remain in the body to help protect the body against future infections with the same organism. This is known as active immunity.
The immune system produces different antibodies for each foreign organism it encounters. This establishes a pool of antibodies that helps protect the body from various different diseases.
Vaccines contain extracts or inactivated forms of bacteria or viruses that cause disease. These altered forms of the organisms stimulate the immune system to produce antibodies against them, but don’t actually cause disease themselves.
The antibodies produced remain in the body so that if the organism is encountered naturally, the immune system can recognise it and attack it, thus preventing it from causing disease.
Each bacteria or virus stimulates the immune system to produce a specific type of antibody, and this means that different vaccines are needed to prevent different diseases.
Immunisation against Typhoid, Hepatitis A and Polio is not critical for short stays in high class accommodation within many tourist resorts in countries otherwise at risk. Adherence to the rules for eating and drinking safely is however, always recommended.
Diphtheria/Tetanus or even Diphtheria/Tetanus/Polio combined vaccine is generally now recommended where tetanus immunisation is indicated and a booster dose required.
The elimination of Poliomyelitis in many regions may cause people to question the need for immunisation. It is generally accepted however, that protection is necessary for travel outside Northern and Western Europe, North America, Australia and New Zealand.
Polio boosters are no longer required for travel to the Americas including South and Central America so long as individuals have had a primary course of polio vaccine during their lifetime.
Nowadays there are very few mandatory immunisation requirements for travellers. Yellow fever is the main example and is only required for parts of Africa, South America and Asia. A certificate of vaccination is often required when entering a country from another country where yellow fever is endemic.
Very often vaccination regulations are a public health measure for the receiving country rather than for the protection of the individual.
Travellers may sometimes be informed by travel companies and embassies that “nothing is needed”. Be warned, this could mean that no vaccination certificates are required for entry into that country. Immunisation may however, still be recommended.
Live vaccines should be administered at least four weeks apart or on the same day. However, the two oral vaccines typhoid and polio are usually separated by at least two weeks due to interference in the gut. Oral typhoid may be given concurrently with yellow fever or HNIG.
Inactivated vaccines can be given simultaneously with any other vaccine but at a different site for patient comfort. Concurrent administration does however, make it difficult to elucidate adverse reactions.
Remember: many health problems facing travellers are not vaccine preventable e.g. malaria and HIV. Guidelines regarding injury prevention, food and water hygiene, protection against insects and safe sex are equally important.