The importance of travel vaccines is often overestimated by travellers and their medical or nursing advisers. Vaccine-preventable disease accounts for 5% of the health risks encountered by travellers.
Diseases do not conform to precise geographical boundaries. The risk of acquiring a disease depends on the individual traveller's risk assessment.
What to recommend
To carry out a risk assessment, ask the patient the following questions:
Where are you going?
Disease risks vary not only from country to country, but from place to place. For example, there is an altitude ceiling above which malaria is not found, and yellow fever is confined mainly to rainforest areas of the countries in which it exists.
How long is the trip?
Disease risks may vary at different times of the year. For example, in some countries, there is a year-long risk of malaria, whereas in others, the risk is in the wet season. Length of stay is also important, and long-stay travellers are at higher risk from most health problems.
How will you travel?
The mode of travel may carry its own health risks, for example, the risk of thromboembolism in long-haul air travel and other prolonged journeys.
Where will you stay?
Low-budget travellers staying in basic accommodation are more at risk from a variety of health problems than those in five-star hotels.
What do you intend to do?
The proposed activities of the traveller are very important in assessing risk. Healthcare and other aid workers are more at risk of blood-borne or person-to-person transmission of infection, while backpackers are more at risk of most infections than package tourists.
While wall charts may give some useful information, the best tool for carrying out a full risk assessment is a regularly updated online database, such as www.travax.nhs.uk
Vaccines for all travellers
Worldwide risk and is a bigger threat in developing countries where contamination of wounds by tetanus spores is more likely to occur.
Now said to be present only in Pakistan, Afghanistan and Nigeria, and in Syrian refugees in Lebanon.
Still present in many developing countries and has re-emerged in former Soviet Union countries.
Travel to countries with poor food and water hygiene
While there is to some extent a worldwide risk, the risk is higher outside northern and western Europe, Australasia and North America. Hepatitis A is the most likely vaccine-preventable risk for most travellers. The following vaccines are available:
- Havrix (GlaxoSmithKline) - adult dose, 1ml; child dose, 0.5ml
- Avaxim (Sanofi Pasteur MSD) - adult dose, 0.5ml
- Vaqta (Sanofi Pasteur MSD) - adult dose, 1ml; child (>1 year)dose, 0.5ml
- Epaxal (Janssen-Cilag), an aluminium-free hepatitis A vaccine, is given as a single IM dose in children aged >1 year and adults. A booster dose after six to 12 months gives protection for at least 10 years.
Found in many developing countries, but the biggest risk is in the Indian subcontinent, although vaccination should also be considered for many African countries and there may be some risk in other parts of Asia and parts of South America.
The following typhoid vaccines are available:
- Typhim Vi (Sanofi Pasteur MSD)
- Typherix (GlaxoSmithKline)
- -Vivotif (Janssen-Cilag) - oral
Cholera does not represent a high risk for most UK travellers. An oral vaccine, Dukoral, is available, which also gives some protection against pathogenic strains of Escherichia coli.
Water-borne infection, and has been referred to above. Infection from close and prolonged exposure to droplet infection is a risk mainly for those involved in teaching, aid work, medical or nursing work.
Vaccines for diseases of close physical contact
Transmitted by person-to-person droplet infection and has been referred to above.
Principal areas of high risk are in sub-Saharan Africa and on the Hajj or Umrah pilgrimages. The available vaccines are:
- Menveo (Novartis Vaccines)
- Nimenrix (GlaxoSmithKline)
Both vaccines are quadrivalent conjugates and suitable for patients aged ≥1 year, as a single IM dose of 0.5ml. Menveo may be given to children aged three months to one year, in two 0.5ml doses one month apart.
A detailed account of BCG vaccination is outside the scope of this article. BCG is a live vaccine given percutaneously by the Heaf gun or by intradermal injection.
- Dr Townend is chairman and honorary fellow, British Global and Travel Health Association
- Part two will discuss vaccinations for remote destinations
- Public Health England. Immunisation against Infectious Disease (The Green Book).
- Zuckerman JN, Jong EC (eds). Travelers' Vaccines (second edition). Shelton CT, People's Medical Publishing House, 2010.