The National Pharmaceutical Pricing Authority (NPPA) has fixed revised retail prices for essential medicines. These include fixing the price of calcium and vitamin D3 tablets and changing the price of anti-rabies immunoglobulin injection. The regulator has also set limits on the retail prices of 39 medicines commonly used to treat high blood pressure, diabetes, heart disease and others. In a separate notification, the authority anti-rabies immunoglobulin The price of injection has been changed to Rs 119.48. Let us understand through this news what anti-rabies immunoglobulin is, how it is prepared, to whom and when it is given and most importantly, how different it is from rabies vaccine.
What is anti-rabies immunoglobulin?
Anti-rabies immunoglobulin (RIG) is a prepared antibody that is given to a person at high risk of getting rabies. This is different from rabies vaccine. While a vaccine prepares the body to produce its own antibodies, RIG provides pre-made antibodies to provide immediate protection.
How is it made?
1. Human Rabies Immunoglobulin (HRIG)
It is made from plasma of healthy humans. These antibodies are isolated from the plasma of people who have previously received the rabies vaccine and have developed sufficient antibodies in their body. After this, safe HRIG is prepared after several steps of purification and virus inactivation process.
2. Equine Rabies Immunoglobulin (ERIG)
It is made from horses. First the horses are immunized by giving them rabies antigen in controlled quantities. Then antibodies are extracted from their blood and purified with modern technology, so that the risk of allergies is reduced. In India, ERIG is used more than HRIG because it is relatively cheaper.
How does it work?
The rabies virus slowly moves from the bite site towards the brain through the nerves. RIG works to immediately inactivate the virus present at the wound site and tries to stop the virus before it gets into the veins. It protects the body until the rabies vaccine shows its effect and starts producing natural antibodies in the body. In simple words, RIG provides immediate protection, whereas the vaccine provides long-term protection.
When is it given?
According to the World Health Organization (WHO), RIG is given in Category III Exposure. This includes cases in which the animal’s bite has resulted in the skin breaking and bleeding, deep wounds, bites at multiple places on the body, or bites on sensitive parts such as the head, neck, face, hands and fingers. Giving RIG is also recommended in high-risk cases involving contact with bats.
Which animal bites pose a risk of rabies?
Rabies virus can occur in all mammalian animals. The greatest danger is considered to be from the bites of infected dogs and cats. Apart from this, monkey, fox, wolf, jackal, bat, raccoon, skunk and mongoose can also spread rabies. If infected, there can be a risk of infection from the bite of domestic animals like cow, buffalo, horse, goat and camel. About 95% of human rabies cases in India are linked to bites from infected dogs. Generally, rabies is not spread by bite or contact with snakes, lizards, crocodiles, turtles, frogs, fish, birds and insects, because these are not mammals. Therefore, RIG is usually not required in these cases.
How is it applied?
As much RIG as possible is injected around and inside the wound, so that the virus can be killed on the spot. If the medicine is left, it is injected into some other muscle of the body. It is never applied at the same place as the rabies vaccine.
When can it be applied?
Ideally RIG should be given on the day of animal bite i.e. Day 0. If this is not possible on the same day, the rabies vaccine can be administered within a maximum of 7 days after starting the vaccine. RIG is usually not given after this, because by then the body starts making its own antibodies in response to the vaccine.
Does every patient get RIG?
No. People who have previously received full rabies vaccination or who have previously received a full course of pre-exposure or post-exposure vaccination do not usually need RIG. In such cases, only booster vaccine is considered sufficient.
Does it have any side effects?
After administration of RIG, pain, swelling and redness may occur at the injection site. Some people may also have mild fever. The possibility of allergy is very less, although in ERIG this risk is considered to be slightly higher than in HRIG. Nevertheless, ERIG prepared with modern technology is considered much safer than before.
Every year lakhs of people in India take anti-rabies treatment after being bitten by dogs and other animals. Once symptoms of rabies begin, it is almost always fatal. Therefore, if bitten by any suspected animal, first of all washing the wound thoroughly with soap and running water for at least 15 minutes, after that getting rabies vaccine as soon as possible and applying anti-rabies immunoglobulin (RIG) where needed is considered to be the most effective way to prevent rabies.
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