Serological comparison of type Asia 1 foot and mouth disease virus isolates from Thailand.

Abstract

Antigenic variation of type Asia 1 foot and mouth disease (FMD) virus in Thailand was examined using a total of 50 field viruses isolated between 1986 and 1992. A two-dimensional serum neutralisation test was used to calculate r values for comparison of these isolates with a reference vaccine strain, Asia 1 Bangkok 1960 (BKK/60). Viruses were also compared to two field isolates, Asia 1 36-2/88 and Asia 1 45/88, and some were compared to another vaccine strain, Asia 1 Nakhon Pathom 1984 (NPT/84). In 80% of cases, field isolates were deemed to be significantly different from the vaccine virus Asia 1 BKK/60, and the distribution of r values indicated that there would be some advantage in selecting a new vaccine strain more closely related to contemporary field strains.