Rabies is one of the oldest diseases, caused by a virus spread through the bite/ scratch of a rabid animal or an infected human, to a healthy person. According to the World Health Organization, every year more than 50,000 people die from the disease. However, the good news is that it is 100% preventable with appropriate prophylactic vaccination.
Vaccination against rabies is a crucial step in having protection against the virus. It can be used in two distinct situations:
Vaccination after exposure had been a common practice for a long time. However, awareness regarding advantages of pre-exposure vaccination is catching up as a proactive measure.
Pre-exposure Prophylaxis (PrEP) is a course of rabies vaccination that is administered to protect a person from getting rabies prior to an exposure to a rabid animal/ any other mode of exposure to rabies virus. People who benefit most from this pre-exposure prophylaxis are the ones who have high risk of coming in contact with saliva, body fluids, or tissues of rabid animals, increasing their risk of rabies. After receiving the pre-exposure vaccine, if anyone gets exposed to rabies, she/ he needs to have only 2 doses of modern tissue/ cell culture anti-rabies vaccine. Also rabies immunoglobulin will not be required as part of post exposure treatment, which is costly and sometimes difficult to procure.
Pre-exposure prophylaxis by administration of rabies vaccines stimulates body’s immune system to produce antibodies against the rabies virus. The antibodies develop within seven to 14 days after being immunized and are able to neutralize the rabies virus on exposure. Pre-exposure vaccination also leads to formation of memory immune cells which stay in the body throughout life. On re-exposure they are able to stimulate production of neutralizing antibodies in short time. However, two more re-exposure vaccination doses are recommended for boosting good amount of antibodies quickly for immediate availability to neutralize any amount of rabies virus that may get into the body on re-exposure.
Pre-exposure rabies vaccination is indicated for those with a relatively high risk of rabies exposure. This includes:
Pre-exposure prophylaxis consists of one dose of intramuscular or intradermal injection of vaccine at one site in deltoid region on days 0, 7 and 21 or 28. Routine booster vaccine doses after primary rabies vaccination are not required. However, regular antibody titer screening is recommended for those who work with live virus and a booster dose is recommended when the titer falls below 0.5 IU/ ml when estimated by RFFIT (Rapid Fluorescent Focus Inhibition Test) method.
Cell/ Tissue cultured Rabies vaccine are considered safe and effective based on numerous clinical studies and past experience of use in millions of people. In some cases, minor local reactions, such as transient pain, itching, swelling, and redness may occur at the site of the injection. These reactions usually subside in a few days.
However, some people may experience side effects such as headache, body pain, feeling unwell, sensation of vomiting and dizziness. Very rarely there may be high fever, abdominal symptoms, swollen glands, multiple red patches, rash, joint pain. Occasionally, there me some severe reaction known as anaphylaxis which may cause shortness of breath and low blood pressure.It is important to intimate the treating doctor immediately in case of any side effect. All side effects can be effectively managed if treated promptly.
Pre-Exposure Rabies vaccination is contraindicated in severe febrile illness, acute or chronic progressive illness and known hypersensitivity to any of the components of the vaccine
The pre-exposure rabies vaccination must be given with caution in: