Kubinski et al.
Tick-borne encephalitis virus: A quest for better vaccines against a virus on the rise
Vaccines 2020; 8, 451; doi:10.3390/vaccines8030451
A comprehensive review article has recently been published dealing with existing TBE vaccines and R&D activities on new TBE vaccines. The main characteristics of the Western European, Russian, and Chinese TBE vaccines have been described and the immunological properties of glycoprotein E, but also prM and NS1 antigens are explained as well as CD4+ and CD8+ T cell responses to various antigens. Antibody-dependent enhancement by pre-existing TBE specific antibodies is a topic in this review and the authors conclude that this phenomenon does not seem to be a major problem, because evidence in vivo is lacking.
The focus of this review lies on novel approaches including vaccination with specific proteins (mainly gE, prM and NS1), virus-like particles, DNA vaccines, RNA vaccines, recombinant adenoviruses, recombinant vaccinia viruses, live attenuated viruses and flavivirus chimera. A number of novel TBE vaccination strategies are in various stages of development and have been tested, however, mainly in pre-clinical models. The presentation and discussion of all these approaches discloses that the path to a novel TBE vaccine enriching or replacing the currently existing highly effective TBE vaccines will be complex and cumbersome.