Pre Exposure Vaccination for Rabies

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 before the exposure to rabies virus, i.e. pre-exposure vaccination
• Vaccination to prevent the development of clinical rabies after exposure has occurred, i.e. post-exposure prophylaxis.

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 rabies prophylaxis (PrEP) (Vaccination):

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.

Advantages of pre-exposure prophylaxis (Vaccination):

• May protect patients when post exposure prophylaxis is delayed;
• Faster antibody responses to post exposure prophylaxis; and
• Reduces the number of post exposure prophylaxis to 2 doses and also there is no by removing the need for rabies immunoglobulin and reducing

How pre-exposure prophylaxis works:

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.

Who should consider receiving pre-exposure vaccination?

Pre-exposure rabies vaccination is indicated for those with a relatively high risk of rabies exposure. This includes:

• Children below 15 years of age

  Children are the most frequently exposed age group and represent about 50% of human exposures in canine rabies infected areas. Children while playing outdoors or walking to school while playing with street dogs are vulnerable to dog bites. These children at this age also have a habit of not reporting to elders if they are bitten, scratched or licked by a dog. Hence, pre-exposure vaccination is a safe and effective method of preventing rabies in children. Children after preventive vaccination usually have a long-lasting immunity against rabies. As a parent, you should also teach your children to tell you if they are ever bitten by any animal.
  WHO also recommends pre-exposure vaccination for children living in highly endemic regions as they are at particular risk of attacks from street dogs.

• Individuals who go for early morning walks or jogging in the lonely lanes or less crowded areas or forests

  If you are a person who goes for early morning walks or jogging, then you are vulnerable to dog bites since unvaccinated community dogs are commonly observed on the streets. There are innumerable bites from stray dogs reported everyday. In such cases, pre-exposure prophylaxis against rabies can be helpful. Also, people who will not have ready access to medical care such as those backpacking to a remote area, should also consider PrEP.

• Pet owners and Animal lovers

  Animal bite is not the only way, one gets rabies. You can also get the disease if the animal licks a cut on your hand or your face. The rabies virus can spread inside the body through mucosal membranes, including your eyes, ears, nose and mouth. So, if you are likely to be involved in activities that bring you into contact with animals, you should consider pre exposure prophylaxis for rabies. In addition, the following people are also considered as high risk population and advised to take vaccination as pre-exposure prophylaxis:
• People who handle animals
• Laboratory workers
• Healthcare workers who come into contact with rabies patients
• People visiting from a part of the world where rabies is not common to part(s) of the world where rabies is common

Pre-Exposure Rabies Vaccination Guide

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.

Could there be undesirable effects from the pre-exposure rabies vaccines?

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 may be 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.

What are the contraindications of pre-exposure rabies vaccination?

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:

• Pregnant and breastfeeding women
• Individuals who have a history of hypersensitivity to any vaccine
• People who are sick or have any infection
• People who are known to have low immunity

Reference:

1. Rabies Vaccinations and immunization. Accessed on 27.11.2020 from: https://www.who.int/ith /vaccines/rabies/en/# .
2. Pre-exposure rabies prophylaxis: a systematic review. Accessed on 27.11.2020 from: https://www.who.int /bulletin/volumes/95/3/16-173039/en/ . Accessed on: 10-11-2020.
3. WHO Expert Consultation on Rabies, Third Report, WHO Technical Report Series 982 and 1012