Why is an immunoglobulin injection given after a tick bite? - briefly
An immunoglobulin injection is given to supply immediate passive antibodies that neutralize tick‑borne pathogens, especially when rapid protection is needed before the body can mount its own response. This pre‑emptive immunity reduces the risk of severe infection such as rabies.
Why is an immunoglobulin injection given after a tick bite? - in detail
A tick bite can introduce viruses such as the tick‑borne encephalitis (TBE) virus or bacteria that cause severe systemic disease. Passive immunization with human anti‑TBE immunoglobulin is employed when immediate protection is required and active vaccination has not yet produced sufficient antibodies.
The injection supplies ready‑made neutralizing antibodies that bind the virus in the bloodstream, preventing it from entering cells and limiting replication. This effect is most pronounced if the serum is administered within 72 hours of the bite, when viral particles are still extracellular.
Key reasons for using the preparation include:
- Rapid onset of protection – antibodies reach therapeutic levels within hours, unlike active vaccines that need weeks to elicit a response.
- Coverage of high‑risk exposures – individuals without prior TBE immunization, those with incomplete vaccination schedules, or patients with immunosuppression benefit from immediate immunity.
- Reduction of disease severity – clinical studies show lower rates of neurologic complications when immunoglobulin is given promptly after exposure.
The recommended regimen consists of a single intramuscular dose of 200 IU per kilogram of body weight, administered in the deltoid or gluteal muscle. Contraindications comprise known hypersensitivity to human immunoglobulin products and severe IgA deficiency with anti‑IgA antibodies. Common adverse effects are mild injection‑site reactions; rare systemic events include headache, fever, or anaphylaxis.
In summary, the injection delivers passive antibodies that neutralize the tick‑borne pathogen before it can establish infection, offering immediate, temporary protection for persons at elevated risk or with insufficient active immunity.