What will happen if a tick bites after a vaccination against tick-borne encephalitis? - briefly
The vaccine generates antibodies that largely prevent encephalitic disease, so a bite from an infected tick seldom leads to severe illness and may result in no symptoms at all. However, sterilizing immunity is not absolute, so any post‑bite symptoms should still be evaluated.
What will happen if a tick bites after a vaccination against tick-borne encephalitis? - in detail
A person who has completed the recommended tick‑borne encephalitis (TBE) immunisation schedule possesses circulating neutralising antibodies that block viral entry into host cells. After the full series, protective titres appear within two to four weeks and persist for several years, reducing the risk of clinical disease by 95 % or more.
If a vaccinated individual is bitten by a TBE‑infected tick, the following points are relevant:
- The virus is usually neutralised before it can replicate, preventing the development of encephalitis.
- In rare cases where the antibody level is insufficient (e.g., incomplete schedule, waning immunity, or individual variation), a mild, flu‑like illness may occur. Symptoms can include fever, headache, myalgia and fatigue, typically lasting a few days.
- Severe neurological manifestations—meningitis, encephalitis, or paralysis—are exceptionally uncommon in this group. When they do appear, they are generally less intense and resolve more quickly than in unvaccinated patients.
- Laboratory testing (serology for TBE‑specific IgM/IgG or PCR) should be performed if any febrile or neurologic signs develop after the bite, regardless of vaccination status.
- Post‑exposure medical advice includes observation for at least ten days, prompt reporting of any symptoms, and, if needed, supportive care. Antiviral therapy is not standard; management remains symptomatic.
Maintaining up‑to‑date booster doses is essential to sustain protective antibody concentrations. Failure to receive boosters can raise susceptibility, making a tick bite more likely to result in infection. Consequently, even after immunisation, vigilance after exposure remains a prudent practice.