Rabies virus is transmitted to humans from exposure to infected animals such as dogs, monkeys, bats and racoons. Exposure is usually through a bite or scratch and once established, rabies infection is invariably fatal despite the availability of all modern treatments. Pre-exposure vaccination is offered to people at high risk of exposure to rabies, such as veterinarians and animal workers living or travelling to countries at risk. Certain activities with extensive outdoor exposure in rural areas – such as running, cycling, hiking, camping, backpacking, etc. – may present significant risk, even if the duration is short. Children are more susceptible to animal bites and pre-exposure vaccination should be particularly considered for visits to countries or areas of rabies risk. Pre-exposure vaccination is also recommended for travel to remote destinations or to areas where immediate access to appropriate medical care/rabies vaccine is limited.
The current WHO guidelines recommend that pre-exposure rabies vaccination consists of three intramuscular doses of vaccine given on days 0, 7 and 21 or 28 (a few days’ variation in the timing is not important). For adults, the vaccine should always be administered in the deltoid area of the upper arm; for young children (less than 1 year of age); the anterolateral area of the thigh is recommended. Rabies vaccine should never be administered in the gluteal area: administration in this manner will result in lower neutralizing antibody titres.
WHO advice also recognises that intradermal administration, when vaccine is injected to the superficial area of the skin, is equally effective. The cost for pre-exposure rabies vaccination is reduced as intradermal vaccination requires a lesser volume of vaccine for administration; the course follows a similar schedule of days 0, 7 and either 21 or 28. This method of administration is an acceptable alternative to intramuscular administration although it is technically more difficult and requires appropriate staff training and qualified medical supervision. Concurrent use of chloroquine or mefloquine (anti-malaria medications) can reduce the antibody response to intradermal application of modern rabies vaccines. People who are currently receiving these preventative treatments for malaria or who are unable to complete the entire three-dose pre-exposure series before starting malarial prophylaxis should therefore receive pre-exposure vaccination by the intramuscular route. Periodic booster injections following intradermal or intramuscular courses are not recommended for general travellers.
In the event of a bite, scratch or other potential exposure to an animal known or suspected to be rabid, individuals who have previously received a complete series of pre- or post-exposure rabies vaccine should receive two booster doses of vaccine. Ideally, the first dose should be administered on the day of exposure and the second 3 days later. This should be combined with thorough wound treatment (see below). Rabies immunoglobulin is not required for patients who have previously received a complete vaccination series.
- Treatment should be commenced as soon as possible after the exposure. Immediately wash the wound with soap/detergent and running water for 5 minutes.
- If possible apply iodine tincture or water based solution of iodine, povidone or ammonium compounds e.g. cetrimide solution 0.15%, or 40-70% alcohol.
- Seek immediate medical advice about the need for rabies vaccination and possible antibiotics to prevent a bite wound infection. Tetanus vaccine may be necessary if this is not up-to-date. For the traveller who has had no previous rabies vaccination, management also entails the injection of rabies immunoglobulin (RIG) mainly around the site of the bite and, starting as soon as possible, up to 5 doses of rabies vaccine- there are various post exposure schedules for this.
As with all vaccines the clinical staff will advise during the travel consultation on all aspects of the procedure including vaccine dose schedule, contraindications to vaccination, any possible interactions with other vaccines or medications, the range of possible adverse effects from the specific vaccine and any queries. Written product information to retain for reference is also provided.
Last Minute Travel
Finally, not all travellers present with adequate time before departure for a full pre-exposure vaccine course, an option in this instance is to give a single dose of rabies. The limited immunity provided by this is of reassurance, however, it should be understood that if less than the recommended three doses of vaccine have been administered pre-exposure, in the event of a possible exposure, a full post-exposure course of vaccinations will be required although RIG will not usually be necessary.