[Detection of neutralizing antibodies in calves after single vaccination against foot-and-mouth disease virus type ASIA 1 in the field].

On June 20th 1984 appeared the first FMD-Type ASIA 1 outbreak in Greece. Around the outbreak all susceptible animals were vaccinated with ASIA 1 vaccine produced by IFFA Mereiux. Three weeks after this first vaccination blood samples have been collected and examined for neutralizing antibodies. From 101 examined calves 37 were younger than 6 months, 63 between 6-11 months and one was 12 months old. The titer of the first group was less than 1.2 in 14 and greater than 1.8 in 8 calves. By the second group (63 animals) the titer was less than 1.2 in 28 and greater than 1.8 in 11 calves. The 12 months old calf had a titer of 2.1. Generally the titer only of 59 out of the 101 examined calves was greater than or equal to 1.2 (59%). That means that the vaccine used had a weak immunogenicity.