Cholera vaccine

What is cholera?

Cholera is an illness cased by a germ (bacterium) called Vibrio cholerae. The illness can be mild and may even not lead to any symptoms in some people. However, in many cases it causes severe diarrhoea, sometimes with being sick (vomiting). This can quickly lead to serious lack of fluid in the body (dehydration) and can even be fatal.

Cholera is usually caught from drinking infected water or eating infected shellfish and other foods. Person-to person spread can occur though.

You can prevent cholera and other water-borne infections by avoiding contaminated water and having good personal and food hygiene. However, it is still important to get the cholera vaccine to ensure more protection.

Examples of people who are likely to be advised to have this vaccine include:

• People going to work in an area of a known cholera outbreak. For example, aid workers, health workers, etc, who will be working in emergency relief camps where cholera has broken out.

• People planing to stay for a long time in an area where there is high risk of cholera - especially any area where there is limited access to medical care.

An oral cholera vaccine (Dukoral®) became available in the UK in 2004. This is now the only cholera vaccine available in the UK. It is not necessary for most destinations. It may be advised for certain people travelling to places where cholera may occur. Your doctor or nurse will advise if you should consider having this vaccine.

In the USA a new single-dose cholera vaccine is available. The vaccine is approved for adults aged 18-64 years who are travelling to an area with an active cholera outbreak. The vaccine - Vaxchora® - has been reported to reduce the chance of severe diarrhoea in 9 people out of 10 at ten days after vaccination and in 8 people out of 10 at three months after vaccination. The safety and effectiveness of Vaxchora® in pregnant or breastfeeding women is not yet known. It is also not known how long protection lasts beyond 3-6 months after getting the vaccine. Side-effects are uncommon but may include tiredness, headache, abdominal pain, nausea and vomiting.

How do I know if I need the cholera vaccine to travel?

The worst affected areas are the Indian subcontinent, the Far East, Africa and South America. The risk to travellers even in infected areas is still quite small.

The cholera vaccine provides protection for up to two years so booster doses are needed to maintain protection.

Boosters are given after two years for people over 6 years old, and after six months for children 2-6 years old. The cholera vaccine can be given at the same time as other injected vaccines.

Note: the vaccine does not provide complete protection. For example, it does not protect against all strains of cholera. Therefore, it is still important that you should be careful with regard to what you eat and drink in the usual way.

There are very few people who cannot have the oral cholera vaccine. It should not be given if:

• You have had a severe reaction to a previous dose of the oral cholera vaccine.

• You have had a severe (anaphylactic) reaction to formaldehyde or to any of the ingredients of the vaccine.

There are currently no data on the safety of this vaccine in pregnant or breastfeeding women. Therefore, if you are pregnant or breastfeeding, the vaccine should only be considered if the risk of cholera is high.

Side-effects from this vaccine are uncommon. Less than 1 person in 100 develops some tummy (abdominal) pains, diarrhoea or a feeling of sickness (nausea) for a short time after taking the vaccine.

The most important part of prevention is to be very careful about personal, food and water hygiene. This is most important in high risk areas where sanitation is poor and where there is a risk of catching cholera. You should not drink any water that is untreated and be very careful what you eat. This not only applies to cholera but also to all sorts of other water-borne infections found in areas of poor sanitation.