Comparative efficacy of virus like particle (VLP) vaccine of foot-and-mouth-disease virus (FMDV) type O adjuvanted with poly I:C or CpG in guinea pigs.

Foot-and-mouth disease (FMD) is one of the most contagious and economically important diseases of cloven-hoofed livestock. Currently used inactivated FMD vaccines have short lived immunity besides risk of handling live virus. We studied recombinant FMD virus like particles (VLPs) encoded by FMDV type O/IND/R2/75 polyprotein genes expressed in Sf9 cells and adjuvanted with CpG or Poly I:C in inducing protective immune response in guinea pigs.

Phylogenetic analysis of Indian serotype Asia1 foot-and-mouth-disease virus isolates revealed emergence and reemergence of different genetic lineages.

Foot-and-mouth-disease virus (FMDV) serotype Asia1 causes significant number of disease outbreaks in India. Indian Asia1 virus isolates were shown to be genetically heterogeneous and of the two lineages (lineage B and lineage C) described in India, lineage C caused majority of the outbreaks. Emergence of a novel divergent lineage (lineage D) within lineage C has been described in 2001.

Assessment of suitability of two serotype A candidate vaccine strains for inclusion in FMD vaccine in India.

The recent type A foot and mouth disease virus field isolates recovered in India are shown to be antigenically quite divergent from the in-use vaccine strain (IND 17/82), warranting the selection of a suitable vaccine strain which can cover this diversity in antigenic spectrum. In earlier studies employing neutralization test with anti-146S rabbit sera raised against eight candidate vaccine strains, IND 81/00 and IND 40/00 belonging to genotype VII were found to offer the best antigenic coverage. In order to assess the credibility of IND 81/00 and IND 40/00 as vaccine strains, 17 recent isolates received during 2005-2006 and representative isolates from older genotypes were subjected to two-dimensional micro-neutralization assay using bovine convalescent serum (against IND 81/00 and IND 40/00) and bovine vaccinate serum (against IND 40/00).

Genotype differentiating RT-PCR and sandwich ELISA: handy tools in epidemiological investigation of foot and mouth disease.

Years of molecular epidemiological surveillance has revealed co-circulation of two antigenically divergent genotypes of foot and mouth disease virus serotype A in India. Genotype differentiating RT-PCR and sandwich ELISA were developed as fast, cost-effective and user-friendly alternatives to 1D region based phylogeny for detection and differentiation of genotype VI and VII. The RT-PCR assay targeting 1D region was found to be more sensitive and authentic in distinguishing genotypes than sandwich ELISA.