How long after a tick bite can a vaccine be given? - briefly
The vaccine should be administered within three days of the bite; beyond that window its effectiveness declines sharply.
How long after a tick bite can a vaccine be given? - in detail
The interval between a tick bite and the administration of a vaccine depends on the disease being prevented. For rabies, post‑exposure prophylaxis (PEP) is recommended as soon as possible after the incident. The first dose of the inactivated rabies vaccine should be given on day 0, with subsequent doses on days 3, 7, and 14 (or 28 for immunocompromised individuals). Rabies immunoglobulin is injected at the same time as the initial vaccine dose, providing immediate passive immunity. Delaying PEP beyond 24 hours reduces efficacy, and a delay of more than 48 hours markedly increases the risk of disease progression.
For Lyme disease, no vaccine is available for post‑exposure use. The standard preventive measure is a single dose of doxycycline (200 mg) taken within 72 hours of the bite, provided the tick was attached for ≥36 hours and the region is endemic. If the time window exceeds 72 hours, antibiotic therapy is still considered based on clinical judgment, but a vaccine cannot be administered after exposure.
Other tick‑borne infections (e.g., anaplasmosis, babesiosis, tick‑borne encephalitis) lack licensed post‑exposure vaccines. Management relies on early antimicrobial treatment rather than immunization.
Key timing points
- Rabies vaccine: first dose on the day of exposure; additional doses on days 3, 7, 14 (or 28).
- Rabies immunoglobulin: administered concurrently with the first vaccine dose.
- Lyme disease prophylaxis: doxycycline within 72 hours; no vaccine option.
- Tick‑borne encephalitis: pre‑exposure vaccination series required; no post‑exposure dose is effective.
Prompt assessment of the bite, identification of the tick species, and evaluation of local disease prevalence are essential for determining the appropriate preventive strategy.