Kälin et al.
Immune response after vaccination against tick-borne encephalitis virus (TBEV) in horses Vaccines. 2024, 12(9):1074. https://doi.org/10.3390/vaccines12091074
Tick-borne encephalitis (TBE) virus infections in horses are typically mild, but they can sometimes manifest with symptoms such as fever, behavioral changes, decreased consciousness, stupor, ataxia, paralysis, and other severe complications. While TBE vaccines provide high levels of protection against the disease in humans, no vaccine has yet been licensed for veterinary use.
A study was conducted on seven healthy mares, aged between 5 and 21 years, to evaluate the immunogenicity of FSME Immun (based on the Neudörfl strain) and to monitor inflammatory markers. The vaccine was administered intramuscularly into the left side of the neck on days 0 and 28. Three mares in the control group did not receive the vaccine.
Initially, seronegative horses showed at least a fourfold increase in antibody concentrations, while initially seropositive horses exhibited a threefold rise in antibodies (as measured by ELISA) following the second vaccination. A tenfold increase in neutralizing titers was observed in all horses after the second dose. However, antibody titers declined within a year, suggesting that booster vaccinations will be necessary to maintain immunity.
No abnormal clinical findings or significant changes in inflammatory markers were observed in any horse throughout the study period.
Further research is needed, including studies with larger sample sizes and challenge trials, to evaluate the effectiveness and safety of TBE vaccination in horses.