title: Emergence of antigenic variants with in serotype A foot and mouth disease virus in India and evaluation of a new vaccine candidate panel.
abstract: Emergence of genetically and antigenically divergent lineages/genotypes and poor intergenotypic antigenic coverage is a major concern in serotype A foot-and-mouth-disease virus (FMDV) in India. In 2009, to cover antigenic diversity emerged in serotype A virus field isolates, IND40/2000 was selected as the new vaccine strain for incorporation in the trivalent FMD vaccine formulation used in India. Although current vaccine strain (IND40/2000) covers most isolates antigenically, a few VP3(59)-deletion group isolates showed low r-value in routine vaccine matching exercise. The VP3(59)-deletion group within genotype 18 emerged first in late part of 2002 and in 2007 causing outbreaks along with non-deletion isolates of the same genotype. In case of emergence or re-emergence of more antigenically divergent isolates in future, a need for a new vaccine candidate to cover maximum isolates of both deletion and non-deletion group may arise. Four alternate candidate vaccine strains (IND281/2003, IND195/2007, IND360/2007 and IND123/2008) were selected based on set criteria and antigenic relationships with field isolates sampled between 2002 and 2009 were analyzed using a micro-neutralization test. Phylogenetic analysis based on capsid region of serotype A isolates revealed existence of two broad distinct clusters (VP3(59)-deletion and non-deletion group) within genotype 18. The VP3(59)-deletion group has diversified genetically with time giving rise to three different sub-lineages (clade18a, 18b and 18c). The present study indicates that the virus candidates IND281/2003 (VP3(59)-deletion group) and IND195/2007 (non-deletion group) can be used as an adjunct or alternative strain to currently used vaccine strain IND40/2000 in case of emergence of more antigenically divergent isolates in future.
authors.affiliation: Project Directorate on Foot-and-Mouth Disease, Indian Veterinary Research Institute Campus, Mukteswar-Kumaon, Nainital 263138, Uttarakhand, India.
authors.forename: Ajjaiah G
authors.initials: AG
authors.lastname: Rudreshappa
authors.forename: Aniket
authors.initials: A
authors.lastname: Sanyal
authors.forename: Jajati K
authors.initials: JK
authors.lastname: Mohapatra
authors.forename: Saravanan
authors.initials: S
authors.lastname: Subramaniam
authors.forename: Ankan
authors.initials: A
authors.lastname: De
authors.forename: Biswajit
authors.initials: B
authors.lastname: Das
authors.forename: Nagendrakumar B
authors.initials: NB
authors.lastname: Singanallur
authors.forename: Anil K
authors.initials: AK
authors.lastname: Jangam
authors.forename: Madhanmohan
authors.initials: M
authors.lastname: Muthukrishnan
authors.forename: Srinivasan A
authors.initials: SA
authors.lastname: Villuppanoor
authors.forename: Bramhadev
authors.initials: B
authors.lastname: Pattnaik
mesh_terms: D000818:Animals; D000940:Antigenic Variation / Q000235:genetics*; D000956:Antigens, Viral / Q000235:genetics*; D036022:Capsid Proteins / Q000235:genetics; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000821:virology*; D005536:Foot-and-Mouth Disease / Q000453:epidemiology* / Q000517:prevention & control*; D029544:Foot-and-Mouth Disease Virus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D007194:India / Q000453:epidemiology; D009500:Neutralization Tests; D010802:Phylogeny; D017384:Sequence Deletion; D014765:Viral Vaccines
chemical_list: D000956:Antigens, Viral; D036022:Capsid Proteins; D014765:Viral Vaccines