Bluetongue vaccines: the past, present and future

Area of Science:

• Veterinary Virology
• Immunology
• Epidemiology

Background:

• Bluetongue (BT) is a significant noncontagious arboviral disease affecting domestic and wild ruminants globally.
• The bluetongue virus (BTV) has 24 recognized serotypes, posing challenges for control due to enzootic cycles involving reservoirs and vectors.
• Current control strategies include animal movement restrictions, vector control, culling, and vaccination, with prophylactic immunization being key.

Purpose of the Study:

• To provide a comprehensive overview of bluetongue virus (BTV) vaccines, from conventional to novel developments.
• To assess the feasibility and efficacy of different vaccine types in controlling BT infection.
• To highlight the importance of vaccine safety, efficacy, and differentiating infected from vaccinated animals (DIVA) capabilities.

Main Methods:

• Review of existing literature on BT vaccines, including attenuated, inactivated, and new-generation platforms.
• Analysis of vaccine efficacy, safety profiles, and DIVA potential.
• Exploration of emerging control strategies such as antivirals and nanotechnology.

Main Results:

• Attenuated vaccines are widely used but raise safety concerns; inactivated vaccines offer better safety and efficacy but require further development for DIVA.
• New-generation vaccines (subunit, virus-like particles, core-like particles, vectored, and recombinant) show promise for DIVA and cross-protection against multiple BTV serotypes.
• While experimentally safe and efficacious, new-generation vaccines require large-scale field trials.

Conclusions:

• Vaccination remains the most practical control measure for bluetongue virus (BTV).
• A shift towards safer and more effective vaccines, including inactivated and novel platforms, is evident.
• Future control may involve a combination of advanced vaccines and alternative strategies like antivirals and nanotechnology.