Anti-rabies immunoglobulin

Anti-rabies immunoglobulin (RIG) is a medication used in conjunction with rabies vaccine to prevent rabies, a deadly virus that affects the central nervous system. Rabies is transmitted through the bite or scratch of an infected animal, most commonly dogs in countries where rabies is endemic. Anti-rabies immunoglobulin provides immediate passive immunity to individuals who have been exposed to the rabies virus, offering protection until the vaccine can stimulate the body's active immune response.

Composition and Types

Anti-rabies immunoglobulin is derived from either human or equine sources. Human rabies immunoglobulin (HRIG) is made from the plasma of donors vaccinated against rabies, while Equine rabies immunoglobulin (ERIG) is produced from the serum of horses immunized with rabies vaccine. HRIG is preferred over ERIG due to a lower risk of side effects, but ERIG may be used in areas where HRIG is unavailable or prohibitively expensive.

Indications

Anti-rabies immunoglobulin is indicated for post-exposure prophylaxis in individuals who have been exposed to rabies and have not been previously vaccinated against the virus. This includes people who have been bitten or scratched by animals suspected to be rabid or who have had contact with the saliva of such animals through mucous membranes or open wounds.

Administration

The administration of anti-rabies immunoglobulin is based on the weight of the patient. It is given as a single dose as soon as possible after exposure to the rabies virus, ideally within the first 24 hours. The immunoglobulin should be infiltrated around and into the wounds if possible, with any remaining volume administered intramuscularly at a site distant from the rabies vaccine injection site to avoid interference with the vaccine's efficacy.

Efficacy and Safety

When used in conjunction with the rabies vaccine, anti-rabies immunoglobulin is highly effective in preventing the onset of rabies symptoms, which are almost always fatal once they appear. Side effects of anti-rabies immunoglobulin are generally mild and may include pain and swelling at the injection site, fever, and headache. Allergic reactions are rare but can occur, especially with ERIG.

Global Availability

The availability of anti-rabies immunoglobulin varies globally, with shortages often reported in regions with high rates of rabies. Efforts are ongoing to improve access to this critical medication in underserved areas.

Conclusion

Anti-rabies immunoglobulin plays a vital role in the prevention of rabies following exposure to the virus. It is a key component of post-exposure prophylaxis, along with the rabies vaccine, in preventing the progression of this deadly disease. Public health initiatives aimed at increasing awareness and availability of both the vaccine and immunoglobulin are crucial in the global fight against rabies.