Rabies Vaccination

Rabies is a fatal viral infection, is usually acquired in humans from the bite of an infected animal. Nearly all deaths in humans worldwide result from the bite of a rabid dog.¹

Between 2000-2005 there were 4 cases of rabies in the UK,² three acquired from dog bites abroad (Philippines, India and Nigeria) and one from the bite of an infected UK bat (2002).³

Active and passive immunisation is available and schedules have been developed for pre-exposure and post- exposure prophylaxis. There is no treatment for rabies.

• Currently cell-culture derived vaccines are used. There are 2 licensed for use in the United Kingdom:
  • Human diploid cell vaccine (HDCV) or Rabies Vaccine BP Pasteur Merieux
  • Purified chick embryo cell rabies vaccine (PCEC) or Rabipur.
  They are freeze dried, inactivated and contain traces of neomycin. They should be stored at 2-8 degrees Celsius and discarded if unused 1 hour after reconstitution. Administration is usually deep subcutaneous or intramuscular, in the deltoid region. They can be used interchangeably.
• New more potent DNA vaccines are being developed.⁴
• Rabies-specific immunoglobulin is available (HRIG) and is derived from the plasma of immunised human donors for passive immunisation.
• Other cell-culture-derived vaccines are available in other countries but these are no longer recommended.

At risk groups

This is available free on the NHS to:

• Laboratory workers handling the virus.
• Workers handling imported animals.
• Licensed bat handlers.
• Workers in at risk jobs, in at risk areas.
• Health workers likely to have contact with infected patients.

It is also recommended, but not free on the NHS to:

• Travellers to high risk areas where there is also limited access to medical care and particularly to easy post-exposure prophylaxis. Up-to-date information on other countries to assess this can be found on the NATHNAC website - see the link below.

Routes of administration and dosage schedules

The options are:

• Primary, pre-exposure protection: give 3 doses, 1 ml deep subcutaneous/intramuscular deltoid region at days 0, 7 and 28. (0,7, 21 or 28 with Rabipur).
• Travellers, not handling animals: give 2 doses, 1 ml as above day 0 and 28. If risk continues give booster at 6-12 months.
• Unlicensed intradermal route for rapid immunisation (e.g. nursing infected patient): 0.1 ml intradermally each limb (0.4mls total).⁵

Reinforcing doses

In UK not necessary unless:

• Risk regular and continuous and post-exposure treatment difficult: 2-3 yearly reinforcing dose.
• Those working with the live virus: serological testing advised 6 monthly.

The schedule used depends on:

• Level of risk (low, medium or high) in the country.
• Type of exposure (history of the animal-stray, likelihood of infection etc).
• The individual's immunity (details of previous vaccinations if any).

If possible expert advice on the appropriate management and schedule should be sought with this outline of information from the Health Protection Agency Virus Reference Department, Colindale, London on 020 8200 4400 or the Communicable Disease Surveillance Centre on 020 8200 6868.

Immediate action at the time

1. Clean the wound under running tap water with soap for 5 minutes. Then treat with 70% alcohol solution or topical iodine solution.⁶
2. Information gathering: name and address of animal's owner to allow follow up. This may require enlistment of help from local officials.
3. Local medical advice should be sought. They are likely to know the level of risk locally and be able to advise on the need for vaccination.

Action on return to this country

1. Wound care as above.
2. Information about the biting animal following up on above information.
3. Information about level of risk in the country using the numbers above.

Summary

These are generally minor including local reactions within 24-48 hours but may be more of a problem with repeated doses of the vaccine. Systemic reactions have been reported as has anaphylaxis. Local reactions with HRIG have been reported.

Hypersensitivity to the vaccine or acute febrile illness are contraindications for pre-exposure prophylaxis.⁶ In pregnancy vaccine should only be given if the level of risk is high for pre-exposure prophylaxis.

• HDCV from Pasteur Merieux (Tel 01628 773200).
• HDCV for pre-exposure with occupational risk via PHLS 020 8200 4400 and for others/travellers from local pharmacies with private prescription.
• Post-exposure-centres in the PHLS Directory-also advise re HRIG availability.