[Epidemiologic evaluation of the immunologic structure of groups with respect to hepatitis A virus]

The members of a newly formed group of persons have been found to be dissimilar in the intensity of their immunity to hepatitis A virus (HAV), the character of changes in the specific antibody level and the time of its retention. In groups with the favorable situation with respect to hepatitis A, the epidemic process takes a latent course. The continuous circulation of the infective agent is ensured by the presence of the asymptomatic and inapparent forms of this infection. Changes in the specific immunostructure of groups with sporadic changes of hepatitis A are directed mainly towards an increase in the proportion of highly immune persons (with the titer of antibodies to HAV exceeding 1:2,000), the number of persons with low and medium antibody levels remaining approximately the same. Under the conditions of the northwestern region, the titer of antibodies to HAV exceeding 1:2,000 in the blood serum ensures the protection of humans from hepatitis A.