The Foot and Mouth Disease Virus Type O Outbreak of 1992 Is Not Related to Vaccine Strain (O/R2/75)

Vaccination is the only pragmatic approach to control foot and mouth disease in India. Strict quality control measures are essential to supply potent vaccine to the field application, in addition to monitoring the performance of the vaccine in the field. During the process of monitoring, an outbreak of FMD in vaccinated animals caused by type “O” virus in Tanjavur district of Tamil Nadu and a type “O” virus from unvaccinated herd of Karnataka were studied. Field isolates and vaccine virus were sequenced and analyzed. Data indicated that the virus from the outbreak in vaccinated cattle was a variant which could escape neutralization by antibodies against vaccine virus. This revised version was published online in August 2006 with corrections to the Cover Date.     

Antigenic Variation in Foot and Mouth Disease Virus Type Asia 1 Isolates Circulated During 1993–95 in India

The antigenic variation in Foot and Mouth Disease Virus (FMDV) is very high. The effective strategy to control the Foot and Mouth Disease (FMD) in India which is a habitat of four serotypes O, A, C and Asia 1, is by regular vaccination, using the vaccine strain most suitable for the local situation. India is an endemic country with the disease being widely distributed. Selection of vaccine strain should therefore need the information on the circulating viruses. Asia 1 causes the second largest number of disease outbreaks in India. As there is no information available with respect to the extent of antigenic variation in FMDV type Asia 1, we have studied FMDV isolates from vaccinated and unvaccinated animals from different parts of the country and compared their relationship with Asia 1 vaccine virus. The immunogenic, hypervariable region of viral protein 1 (VP1) gene was amplified by RT-PCR and sequenced. Analysis of sequence data showed that the viruses from two field outbreaks of Southern India were closely related to each other when compared to the isolate from the North and all the three isolates are away from the vaccine virus. This revised version was published online in July 2006 with corrections to the Cover Date.