The repair activity of DNA was studied by variola vaccine virus reactivation and induced mutagenesis tests in the peripheral blood lymphocytes of children living in areas with an increased level of ionizing radiation due to breakdown at the Chernobyl' nuclear power station. A more profound repair disturbance was revealed in children living on strictly controlled territories and born after the disaster, compared to those born before it, and children living in areas where the radiation level does not exceed background values. The disturbances were characterized by increased induced mutagenesis and decreased reactivation of the variola vaccine virus. No changes in the degree of DNA repair synthesis were registered in any of the groups studied.
Was vaccination the only cause of the decline of smallpox in Norway during the 19th century? This regional study focuses on the history of the disease in Telemark county with special emphasis on the last, extensive epidemic in 1868. In addition to vaccination, other possible causal relations are discussed. In Telemark, smallpox seems to have been relatively mild in the 19th century with the exception of the epidemics at the end of the 1830s and in 1868. In 1868 the disease spread along the main transportation routes northward through the western part and eastward through the more densely populated districts along the coast. The importance of vaccination is apparent from the fact that the municipalities with the lowest annual percentage of newborns vaccinated were most heavily struck by the epidemic. Despite vaccination procedures, both adults and unvaccinated children were groups at risk. Local initiatives--especially isolation and revaccination--largely prevented or restricted outbreaks of smallpox. It seems that the efforts of the district medical officers and local health administrators after 1860 were of decisive importance for the decline in smallpox cases in the period in question.
Virological and immunofluorescent methods were applied to the study of the distribution of the smallpox vaccine virus in the organs and tissues of rabbits immunized orally. It appeared that the vaccinal process developed with a predominant localization of the antigen in the regional (in respect to the site of administration) lymph nodes; the virus was revealed in the cell cytoplasm.
