Rabies vaccine
The rabies vaccine is a vaccine used to prevent rabies.[11] There are several rabies vaccines available that are both safe and effective.[11] Vaccinations must be administered prior to rabies virus exposure or within the latent period after exposure to prevent the disease.[12] Transmission of rabies virus to humans typically occurs through a bite or scratch from an infectious animal, but exposure can occur through indirect contact with the saliva from an infectious individual.[12]
Vaccine description
RabAvert, Rabipur, Rabivax, others
- none
Doses are usually given by injection into the skin or muscle.[11] After exposure, the vaccination is typically used along with rabies immunoglobulin.[11] It is recommended that those who are at high risk of exposure be vaccinated before potential exposure.[11] Rabies vaccines are effective in humans and other animals, and vaccinating dogs is very effective in preventing the spread of rabies to humans.[11] A long-lasting immunity to the virus develops after a full course of treatment.[11]
Rabies vaccines may be used safely by all age groups.[11] About 35 to 45 percent of people develop a brief period of redness and pain at the injection site, and 5 to 15 percent of people may experience fever, headaches, or nausea.[11] After exposure to rabies, there is no contraindication to its use, because the untreated virus is virtually 100% fatal.[11][13]
The first rabies vaccine was introduced in 1885 and was followed by an improved version in 1908.[14] Millions of people globally are vaccinated against the virus.[11] It is on the World Health Organization's List of Essential Medicines.[15][16]
Medical uses[edit]
Before exposure[edit]
The World Health Organization (WHO) recommends vaccinating those who are at high risk of the disease, such as children who live in areas where it is common.[11] Other groups may include veterinarians, researchers, or people planning to travel to regions where rabies is common.[17] Three doses of the vaccine are given over a one-month period on days zero, seven, and either twenty-one or twenty-eight.[11][17]
After exposure[edit]
For individuals who have been potentially exposed to the virus, four doses over two weeks are recommended, as well as an injection of rabies immunoglobulin with the first dose.[18] This is known as post-exposure vaccination.[19] For people who have previously been vaccinated, only a single dose of the rabies vaccine is required.[19] However, vaccination after exposure is neither a treatment nor a cure for rabies; it can only prevent the development of rabies in a person if given before the virus reaches the brain.[19] Because the rabies virus has a relatively long incubation period, post-exposure vaccinations are typically highly effective.[11]
Additional doses[edit]
Immunity following a course of doses is typically long lasting, and additional doses are usually not needed unless the person has a high risk of contracting the virus.[11] Those at risk may have tests done to measure the amount of rabies antibodies in the blood, and then get rabies boosters as needed.[17] Following administration of a booster dose, one study found 97% of immunocompetent individuals demonstrated protective levels of neutralizing antibodies after ten years.[20]
Safety[edit]
Rabies vaccines are safe in all age groups.[11][21] About 35 to 45 percent of people develop a brief period of redness and pain at the injection site, and 5 to 15 percent of people may experience fever, headaches, or nausea.[11] Because of the certain fatality of the virus, receiving the vaccine is always advisable.[11]
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.[11] Their use is thus not recommended by the World Health Organization.[11]
Types[edit]
The human diploid cell rabies vaccine (HDCV) was started in 1967. Human diploid cell rabies vaccines are inactivated vaccines made using the attenuated Pitman-Moore L503 strain of the virus.[22]
In addition to these developments, newer and less expensive purified chicken embryo cell vaccines (CCEEV) and purified Vero cell rabies vaccines are now available and are recommended for use by the WHO.[11] The purified Vero cell rabies vaccine uses the attenuated Wistar strain of the rabies virus, and uses the Vero cell line as its host. CCEEVs can be used in both pre- and post-exposure vaccinations. CCEEVs use inactivated rabies virus grown from either embryonated eggs or in cell cultures and are safe for use in humans and animals.[11][23]
The vaccine was attenuated and prepared in the H.D.C. strain WI-38 which was gifted to Hilary Koprowski at the Wistar Institute by Leonard Hayflick, an Associate Member, who developed this normal human diploid cell strain.[24][25]
Verorab, developed by Sanofi-Aventis and Speeda, developed by Liaoning Chengda are purified vero cell rabies vaccine (PVRV).[26][27] The first is approved by the World Health Organization.[28] Verorab is approved for medical use in Australia and the European Union and is indicated for both pre-exposure and post-exposure prophylaxis against rabies.[4][10]
Society and culture[edit]
Economics[edit]
When the modern cell-culture rabies vaccine was first introduced in the early 1980s, it cost $45 per dose, and was considered to be too expensive. The cost of the rabies vaccine continues to be a limitation to acquiring pre-exposure rabies immunization for travelers from developed countries. In 2015, in the United States, a course of three doses could cost over US$1,000, while in Europe a course costs around €100. It is possible and more cost-effective to split one intramuscular dose of the vaccine into several intradermal doses. This method is recommended by the World Health Organization (WHO) in areas that are constrained by cost or with supply issues. The route is as safe and effective as intramuscular according to the WHO.[33]