Leptospirosis vaccines: Current view

2^nd Indo-Global Summit & Expo on Veterinary

October 26-28, 2015 Hyderabad, India

Satish K Srivastava

Indian Veterinary Research Institute, India

Posters-Accepted Abstracts: J Veterinar Sci Technol

Abstract :

Leptospirosis has in recent years emerged as one of the priority diseases in the country as it is responsible for substantial economic losses to the farmers as a result of various reproductive disorders it causes in animals such as abortions, still birth and repeat breeding including mastitis and agalactia. Research on the development of a suitable vaccine for control of the disease has continued since last 50 years with mixed findings. Presently we have inactivated whole cell vaccines which comprise of one or preferably several Leptospira serovars with or without adjuvant to provide a broad range of immunity. Selection of serovars in preparing these vaccines depends on the prevalence of the serovars in the target area or animal population. Repeated vaccinations are required to generate protective immunity in animals which may not last for more than 6 months. A few such multivalent killed commercial vaccines are currently in use in countries such as USA, Australia, New Zealand and UK. Due to short lived immunity generated by these vaccines, development of live vaccines was attempted using highly prevalent serovars, Pomona and icterohaemorrhagiae. Though these vaccines generated higher level of immunity in animals, however, the problem of maintenance of the vaccine strains and reversion to the virulent form have been the constraints in their wider acceptability. Subunit vaccines prepared from surface proteins separated from outer cell membrane have been a much accepted option. A few protein sub units targeted for such studies are 39 kDa, Omp L1, Lip41, LipL32 and Lig proteins. Efforts on the expression of some of these proteins for vaccination have been partly successful. Latest approaches for vaccination include use of DNA construct using flaB2 gene and outer membrane protein genes of serovar Lai and Hap1/LipL32 gene of serovar autumnalis or Grippotyphosa. Studies on the improvements in the existing vaccines and development of new generation vaccines are continuing.

Biography :

Email: sksrivastava1093@gmail.com