Rabies vaccine

Rabies vaccine

Vaccine description
Target disease	Rabies
Type	Killed/Inactivated
Clinical data
AHFS/Drugs.com	monograph
MedlinePlus	a607023
Identifiers
ATC code	J07BG01
ChemSpider	none
NY (what is this?)  (verify)

Rabies vaccine is a vaccine used to prevent rabies.^[1] There are a number of vaccines available that are both safe and effective. They can be used to prevent rabies before and for a period of time after exposure to the virus such as by a dog or bat bite. The immunity that develops is long lasting after three doses. Doses are usually given by injection into the skin or muscle. After exposure vaccination is typically used along with rabies immunoglobulin. It is recommended that those who are at high risk of exposure be vaccinated before potential exposure. Vaccines are effective in humans and other animals. Vaccinating dogs is very effective in preventing the spread of rabies to humans.^[1]

Rabies vaccines may be safely used in all age groups. About 35 to 45 percent of people develop a brief period of redness and pain at the injection site. About 5 to 15 percent of people may have fever, headaches, or nausea. After exposure to rabies there is no contraindication to its use. Most vaccines do not contain thimerosal. Vaccines made from nerve tissue are used in a few countries, mainly in Asia and Latin America, but are less effective and have greater side effects. Their use is thus not recommended by the World Health Organization.^[1]

The first rabies vaccine was introduced in 1885, which was followed by an improved version in 1908.^[2] Millions of people globally have been vaccinated and it is estimated that this saves more than 250,000 people a year.^[1] It is on the World Health Organization's List of Essential Medicines, the most important medication recommended for a basic health system.^[3] The wholesale cost is between 44 and 78 USD for a course of treatment as of 2014.^[4] In the United States a course of rabies vaccine is more than 750 USD.^[5]

Medical uses

The World Health Organization recommends vaccinating in those who are at high risk of the disease including children who live in areas where it is common.^[1] Four doses are given over a one-month period.^[1]

Additional doses

Immunity following a course of doses is typically long lasting.^[1] Additional doses are not typically needed except in those at very high risk.^[1] Following administration of a booster dose, one study found 97% of immuno-competent individuals demonstrate protective levels of neutralizing antibodies at 10 years.^[6]

Types

The human diploid cell rabies vaccine (H.D.C.V.) was started in 1967. Human diploid cell rabies vaccines are inactivated vaccines made using the attenuated Pitman-Moore L503 strain of the virus.^[7] Human diploid cell rabies vaccines have been given to more than 1.5 million people as of 2006.

In addition to these developments, newer and less expensive purified chicken embryo cell vaccine, and purified Vero cell rabies vaccine are now available. The purified Vero cell rabies vaccine uses the attenuated Wistar strain of the rabies virus, and uses the Vero cell line as its host.

History

Virtually every infection with rabies resulted in death until two French scientists, Louis Pasteur and Émile Roux, developed the first rabies vaccination in 1885. This vaccine was first used on a human on July 6, 1885, on nine-year-old Joseph Meister (1876–1940), who had been mauled by a rabid dog.^[8]

Their vaccine consisted of a sample of the virus harvested from infected (and necessarily dead) rabbits, which was weakened by allowing it to dry for 5 to 10 days. Similar nerve tissue-derived vaccines are still used now in some countries, and while they are much cheaper than modern cell culture vaccines, they are not as effective. Neural tissue vaccines also carry a certain risk of neurological complications.^[9]

Other animals

Baits with vaccine for oral vaccination

Machine for distribution of baits from airplane

Aside from vaccinating humans, another approach was also developed by vaccinating dogs to prevent the spread of the virus. In 1979 the Van Houweling Research Laboratory of the Silliman University Medical Center in Dumaguete in the Philippines, then headed by Dr. George Beran,^[10] developed and produced a dog vaccine that gave a three-year immunity from rabies. The development of the vaccine resulted in the elimination of rabies in many parts of the Visayas and Mindanao Islands. The successful program in the Philippines was later used as a model by other countries, such as Ecuador and the Yucatan State of Mexico, in their fight against rabies conducted in collaboration with the World Health Organization.^[11]

In Tunisia a rabies control program was initiated to give dog owners free vaccination to promote mass vaccination which was sponsored by their government. The vaccine is known as Rabisin (Mérial), which is a cell based rabies vaccine only used countrywide. Vaccinations are often administered when owners take in their dogs for check-ups and visits at the vet.^[12]

Pre-exposure immunization has been used on domesticated and wild populations. In many jurisdictions, domestic dogs, cats, ferrets, and rabbits are required to be vaccinated.

There is also vaccination in pellet form which can be left out for wild animals to produce a "herd-immunity" effect.^[13] Oral vaccination against rabies is a preventive measure to eradicate rabies in wild animals, vectors of disease, mainly foxes, raccoons, raccoon dogs, coyotes and jackals, but also can be used for dogs in developing countries.^[14] Baits are distributed by airplanes in rural areas and by hand in urban and suburban areas. The idea of wildlife vaccination was conceived during the 1960s, and modified-live rabies viruses were used for the experimental oral vaccination of carnivores by the 1970s. The development of safe and effective rabies virus vaccines applied in attractive baits resulted in the first field trials in Switzerland in 1978.^[15]

Imrab is an example of a veterinary rabies vaccine containing the Pasteur strain of killed rabies virus. Several different types of Imrab exist, including Imrab, Imrab 3, and Imrab Large Animal. Imrab 3 has been approved for ferrets and, in some areas, pet skunks.^[16][17]

Recombinant rabies vaccine

Aerially distributed wildlife rabies vaccine in a bait from Estonia.

Oral rabies vaccine baits

In 1984 researchers at the Wistar Institute developed a recombinant vaccine called V-RG by inserting the glycoprotein gene from rabies into a vaccinia virus.^[18] The V-RG vaccine has since been commercialised by Merial.^[19] It is harmless to humans and has been shown to be safe for various species of animals that might accidentally encounter it in the wild, including birds (gulls, hawks, and owls).^[20]

V-RG has been successfully used to prevent outbreaks of rabies in wildlife. The vaccine is stable under relatively high temperatures and can be delivered orally, making mass vaccination of wildlife possible by putting it in baits. The plan for immunization of normal populations involves dropping bait containing food wrapped around a small dose of the live virus. The bait would be dropped by helicopter concentrating on areas that have not been infected yet. In November 2008, Germany had been free of new cases for two years and is therefore currently believed to be rabies-free, together with a few other countries. A strategy of vaccinating “neighborhood dogs” in Jaipur, India, combined with a sterilization program, has also resulted in a large reduction in the number of human cases.^[21]

References