TRAVEL VACCINES

International travel is undertaken by large, and ever increasing, numbers of people for professional, social, recreational and humanitarian purposes. This extensive population flow can increase the threat of transmission of infectious disease and gives rise to a corresponding public health problem[1][2].
Travel to many areas of the world can expose the traveller to serious and potentially fatal infectious diseases, some of which could be prevented by vaccination. It is advisable that all people planning travel should know about the potential hazards of the countries they are travelling to and learn how to minimise their risk of acquiring these diseases.

How can I check what vaccines I will need?
The range of vaccines needed by the traveller depends on the countries visited, the activities planned, where the traveller is staying and how long the visit will last.
There are only two vaccines which are compulsory for entry into certain countries - yellow fever if entering or arriving from an area where yellow fever is endemic, and meningococcal meningitis if attending the Muslim religious pilgrimage, the Hajj or Umrah, in Mecca, Saudi Arabia.
The traveller should ask his or her practice nurse or general practitioner (GP) for specific advice on requirements for their chosen destination. Information regarding the vaccines recommended for travellers can also be found on the website of the National Travel Health Network and Centre3 [http://www.nathnac.org/travel].

When should I get my vaccines?
It is important to seek advice either as soon as the traveller knows when and where he or she is travelling to or at least six weeks before departure[3]. Many travellers believe that they can be vaccinated just days before travel, but some vaccines need more than one dose and all vaccines need time for protection to develop in their body. Even if you only have a few days before travelling, it is still worth seeking advice. This is also an opportunity to find out about other diseases which cannot be prevented by vaccination and advice on other health matters.
For the regular business traveller to areas of the world where vaccine-preventable diseases are common, it is advisable to keep up to date with vaccinations.

HEPATITIS A
Hepatitis A is a viral disease which is easily transmitted via the consumption of contaminated food or drink. The disease is one of the most common vaccine-preventable disease among unprotected travellers[4] and the risk to the unprotected individual is thought to be between six and 30 cases per 100,000 travellers per month[4]. Hepatitis A is highly endemic in the Indian sub-continent, Sub-Saharan and North Africa, and parts of the Far East (not Japan), South and Central America, and the Middle East. The risk is greater for those travellers who travel outside the usual tourist routes and eat or drink under conditions of poor hygiene. Despite this, hepatitis A can also be caught in more developed areas.

MENINGOCOCCAL MENINGITIS
Meningococcal meningitis is caused by a bacterium called Neisseria meningitidis and occurs worldwide. It is most prevalent in the ‘African meningitis belt’, which extends across the dry, savannah parts of sub-Saharan Africa from Senegal in the west, to Ethiopia in the east. For the last few years, all pilgrims travelling for the Hajj and Umrah in Mecca have been asked to provide a vaccination certificate.

POLIOMYELITIS (polio)
The risk of polio is low to the average international traveller. Polio has been eradicated from most countries in the world and only six countries remain polio endemic (Nigeria, Niger, Egypt, Pakistan, Afghanistan, India), although a lapse in vaccine coverage in Nigeria led to recurrence of polio in several previously polio free African countries. This viral disease is spread through faeces and saliva or through close contact with an infected person.
Vaccination against polio is part of the routine immunisation programme in the UK [http://www.immunisation.nhs.uk/Immunisation_Schedule], but it is worth checking before travelling that you are up to date.

TETANUS
Tetanus is caused by a poison (toxin) produced by the bacterium Clostridium tetani and is found in every country in the world. The disease is caused when the bacteria enter the body through a deep wound. Everyone should be protected against tetanus whether they are travelling abroad or not.
Vaccination against tetanus is part of the routine immunisation programme in the UK [http://www.immunisation.nhs.uk/Immunisation_Schedule], but it is worth checking before travelling that you are up to date.

DIPHTHERIA
Diphtheria is caused by a poison (toxin) produced by a bacterium called Corynebacterium diphtheriae. The disease is spread through infected droplets of saliva. Recent outbreaks of diphtheria have occurred in Eastern Europe. The main regions where diphtheria currently occurs are Russia and several other states of the former Soviet Union but the disease is also common in Africa, South America, India and South-East Asia[5]. Everyone should be protected against diphtheria whether travelling abroad or not.
Vaccination against diphtheria is part of the routine immunisation programme in the UK [http://www.immunisation.nhs.uk/Immunisation_Schedule], but it is worth checking before travelling that you are up to date.

TYPHOID FEVER
The risk of typhoid fever is thought to be in the region of 17.3 cases per 100,000 travellers who travel to India, Pakistan and Bangladesh[6]. The disease is spread by contaminated food and drink. Each year around 200 cases of typhoid are imported into the UK by unvaccinated travellers[7].

YELLOW FEVER
Yellow fever is a viral disease which is transmitted through the bite of an infected mosquito. It occurs in the yellow fever zone, which includes countries in tropical Africa and South America. Yellow fever infection is very dangerous and can cause death in more than 50% of patients[8]. For some countries in Africa and South America, a certificate of vaccination against yellow fever is mandatory for entry into the country, while other countries demand a certificate (International Certificate of Vaccination or Prophylaxis) if the traveller is arriving from a country where yellow fever is common.

HEPATITIS B
Hepatitis B is a viral infection of the liver. The disease is spread through contact with blood and other infected bodily fluids. Transmission routes are similar to those for HIV although hepatitis B is considered to be up to 100 times more infectious than HIV[9]. Hepatitis B is very common in some parts of the world such as Africa, South-East Asia and parts of South America, and may have fatal long-term complications. Medical or dental treatment in these areas is a risk and those who may require treatment, including frequent or longer-stay travellers, young children in contact with the local population, people with chronic medical conditions, or those travelling for medical care should consider vaccination. Hepatitis B should also be considered for those that participate in activities that might put them at risk for medical or dental treatment, including sporting activities, those who travel to remote areas, or aid work. As accidents and illness are unpredictable, it is important to be aware of how the virus is transmitted, to take preparations such as sterile surgical kits, and as appropriate to be vaccinated. Hepatitis B can also be transmitted sexually.

RABIES
Most travellers are unaware of the risk of rabies while they are abroad. The disease is transmitted in the saliva of infected animals, usually through a bite - although licking alone can transmit rabies if there are skin abrasions. With the exception of one known case, rabies is invariably fatal if left untreated. The World Health Organization estimates that there are more than 55,000 deaths globally every year, with 95% of human deaths occurring in Asia and Africa[10]. The aim of the rabies immunisation programme is to protect those who are at most risk of exposure to rabies.

JAPANESE ENCEPHALITIS
Japanese encephalitis is a viral disease transmitted through the bite of infected mosquitoes. It occurs in South East Asia and the Far East where it is endemic in rural areas. Highest transmission rates occur when mosquitoes are most active - during and just after wet seasons - though seasonal patterns vary within individual countries and from year to year. Immunisation is recommended for individuals at high risk of exposure through travel or in the course of their occupation.
11 National Travel Health Network and Centre. Heath Information Sheet. Tick Borne Encephalititis. http://www.nathnac.org/pro/factsheets/tick_borne.htm (accessed July 2009)

TICK BORNE ENCEPHALITIS
This viral disease is spread by ticks which live in the forest areas of Northern and Central Europe and Scandinavia[11].
There are three different types of tick-borne encephalitis virus[11]:

• Western European - occurs mainly in western and central European countries, particularly in forest and mountainous regions.

• Far Eastern - occurs in eastern Russia and some countries in East Asia, particularly in forested regions of China and Japan.

• Siberian TBE - occurs in Siberia.

Tick-borne encephalitis vaccine is used for the protection of individuals at high risk of exposure to the virus through travel or employment.

1 World Health Organization. International Travel and Health. Jan 2009. http://www.who.int/ith/ITH_2009.pdf (accessed July 2009)
2 Health Protection Agency. Foreign Travel-associated illness. Travel Trends. 2007. http://www.hpa.org.uk/web/HPAwebFile/HPAweb_C/1194947314350 (accessed July 2009)
3 NaTHNaC. Health Information Sheets http://www.nathnac.org/travel/factsheets/index.htm (accessed July 2009)
4 NaTHNaC. Travel Health Information Sheets. Hepatitis A. http://www.nathnac.org/pro/factsheets/hep_a.htm
5 Department of Health. Immunisation against Infectious Disease – “The Green Book” - Diptheria. 2006: 109-1256 National Travel Health Network and Centre. Heath Information Sheet. Typhoid and Paratyphoid http://www.nathnac.org/pro/factsheets/typhoid.htm (accessed July 2009)
6 National Travel Health Network and Centre. Heath Information Sheet. Typhoid and Paratyphoid
7 Health Protection Agency. Pilot of enhanced surveillance of enteric fever in England, Wales and Northern Ireland. 1st May 2006-30 April 2007.
8 Department of Health. Immunisation against Infectious Disease – “The Green Book”: Yellow Fever. 2006: 443-454
9 World Health Organization. Hepatitis B (Factsheet No. 204). http://www.who.int/mediacentre/factsheets/fs204/en/ (accessed July 2009)
10 World Health Organization. (Rabies Factsheet No. 99) http://www.who.int/mediacentre/factsheets/fs099/en/ (accessed July 2009)
11 National Travel Health Network and Centre. Heath Information Sheet. Tick Borne Encephalititis. http://www.nathnac.org/pro/factsheets/tick_borne.htm (accessed July 2009)

UK VACCINE INDUSTRY GROUP  August 2009