Question

A combination of human rabies immunoglobulin and the rabies virus is administered

• A. as a preventative measure before an individual encounters an animal bite
• B. as a preventative measure when a non-vaccinated individual encounters an animal bite
• C. as a preventative measure when a vaccinated individual encounters an animal bite
• D. Both b and c

Answer 1

The correct option is B as a preventative measure when a non-vaccinated individual encounters an animal bite

Rabies is a deadly viral disease caused by the Rabies virus. The pathogen spreads to humans or animals through the bite of an infected animal as the virus resides in its saliva. The virus enters the body through a muscle and gradually travels up to the brain and the salivary glands. The symptoms start appearing when the virus reaches the brain and starts causing considerable damage.

Initially the patient experiences flu-like symptoms such as fever, headache, weakness and general discomfort. As the disease progresses, acute symptoms of brain damage such as hallucinations (seeing things which are not real), hydrophobia (fear of water), insomnia (inability to sleep) etc., start appearing.

Figure : Common symptoms of rabies

The incubation period (the time period between the entry of the virus and the appearance of symptoms) can vary from a few weeks to months. Generally the risk of encountering rabies can be prevented by vaccinating the pets with the anti rabies vaccine. Pet owners need not vaccinate themselves as the transmission of the virus through non-bite routes is rare. Only laboratory workers who might have the risk of inhaling aerosolized viral particles should receive the anti rabies vaccine. So option a is incorrect.

A combination of human rabies immunoglobulin (HRIG) and the rabies virus is administered only when a non-vaccinated person encounters an animal bite. While the vaccine triggers the body to build up immunity against the Rabies virus, the ready-made human rabies immunoglobulins will immediately start neutralising the pathogen entered through bite. This reduces the risk of a severe infection. Hence option b is correct.

If a vaccinated person encounters an animal bite, then he or she should receive only the vaccine and not HRIG. This is because such individuals already have preformed antibodies in their system to resist infection. So option c is incorrect.