Salat et al.
Development and testing of a new tick-borne encephalitis vaccine candidate for veterinary use.
Vaccine, in press, https://doi.org/10.1016/j.vaccine.2018.10.034
While most TBE infections are acquired by tick bites, a less frequent route of infection is associated by the consumption of unpasteurized milk and milk products from infected ruminants, especially goats, sheep and cows. Alimentary infections mostly occur in Eastern/Southeastern Europe and the Baltic States (see snapshots of week 33, 14, 13 and the newsletter of April). No TBE vaccine has yet been licensed for veterinarian use. The authors describe the development of a new veterinarian TBE vaccine based on the TBE virus strain Hypr (European subtype). This is a formaldehyde-inactivated whole virus vaccine adjuvanted with aluminum hydroxide (Alhydrogel). After three doses, mice developed specific antibodies (measured by ELISA and neutralization test) and were fully protected when challenged with the vaccine strain and also with strain 9001 (isolated from ticks collected in the Czech Republic). Neutralizing antibodies were also developed in sheep. In vaccinated sheep, no specific RNA could be detected after challenge with TBE strain 9001. In vaccinated ewes, no TBE virus could be detected in milk. This may be a promising new TBE vaccine candidate for veterinarian use – for farm animals and pets like dogs.