2

as organizational-cum-administrative and quarantine measures.

The second zone contained six districts where foot-and-mouth
disease first occurred in December 1965 - January, 1966. In all
these districts, the cattle underwent vaccination in combination
with quarantine measures at the very beginning of the outbreak.

In the third zone there were seven districts situated (with
the exception of the Odesaa district ) in the western part of the
republic. In these districts the epizootics broke out mainly in
February - March, 1966. The cattle received prophylactic foot-and-
mouth disease vaccination even before the main outbreak of the
disease.

The regions of Ivano-Frankovska and Zakarpatia were free of
foot-and-mouth disease in the period of 1965 - 1966. The efficacy
of vaccination was estimated according to the opinion of many epizootiologists,
who stated that an epizootic was over if 85% of the
susceptible animals were immune.

In the first zone (Figure 1) where the foot-and-mouth
disease type A22 had good chances of spreading before vaccinations
began, the efficacy of vaccination was low because of the delay in
vaccinations. 69.3% of all the affected foci fell in this region
with 74.6% of cattle having been affected in the entire republic.

A sharp fall in the epizootics in this zone was marked 1.5
months earlier than shown by theoretical calculations and they
were over in 7 months after beginning with over 60% animals having
become immune as a result of pulling over or vaccination.

In the second zone (Figure 2) owing to large-scale and very
early use of prophylactic vaccination, 79.1% of cattle escaped
being affected by foot-and-mouth disease. In this group an animal
that did not fall sick had received 1.9 shots of anti-foot-and-
mouth disease vaccine.

22.8% of all the affected foci fall in this group with 20.9%
of cattle that suffered from foot-and-mouth disease in the course
of the epizootics. The factual period of the epizootics coming to
an end was a month later than the calculated data, 100% of the
animals being immune.

2.