Oral rabies vaccination

Dog rabies control programs by parenteral vaccination in developing countries often fail because an insufficient number of dogs can be vaccinated.

Oral vaccination of foxes in some European countries and wildlife in several US states has been effective in the control of wildlife rabies. Mass oral vaccination of stray dogs is proposed as a rabies control measure in stray dog populations.

An example a palatable bait. The oral vaccine would be included in a sachet in the center of the bait.

Requirements for an oral rabies vaccine

• Safety - Oral rabies vaccines intended for dogs should be safe.The close association between humans and dogs increases the likelihood of direct exposure of humans to vaccine baits during oral vaccination programs.
• Efficacy - the vaccine must be effective when taken in orally
• Palatability - the bait used must be readily acceptable by the target species.
• Effective distribution - The vaccine baits must be effectively distributed to ensure that a sufficient proportion of the population is vaccinated to make the campaign effective.
• Measurability - A system to allow the measurement of vaccine uptake in target populations.
  • Serology - for direct measurement of antibodies post vaccination. The Rapid Fluorescent Focus Inhibition Test (RFFIT) is most commonly used. This test is laborious for large numbers of samples and the development of a suitable ELISA test would be preferable.
  • In some cases a marker such as tetracycline may be included in the vaccine.

Distribution methods

Vaccines are incorporated in edible baits and distributed in rabies enzootic areas. During the US and European vaccination campaigns this was done by dropping baits from aeroplanes over the target areas. Vaccines may also be spread manually e.g. by farmers and hunters.

For the vaccination of stray or ownerless dogs, baits could be presented manually in areas where the dogs tend to congregate to eat and/or sleep e.g. garbage disposal sites. After a certain time period uneaten baits would be removed.

For more information about oral rabies vaccines and vaccination see Intervet oral rabies vaccine.