BCG vaccination: issues of fuzzy logic in assessing its effectiveness

Abstract

Background. Vaccination, as a method of specific prevention, is more than 100 years old. Over the years, there have been significant changes in living standards, children’s health, and immunology. The issues of the effectiveness of vaccination, the effectiveness of chemotherapy, and the need for revaccination are relevant in modern conditions. Aim. To evaluate long-term BCG vaccination data among the medical university students with assessment of the effectiveness of vaccination, and MBT infection during 20 years of follow-up. Materials and methods. 274 students of the medical university took part in the study, medical records were used (form No. 112/y). Records of BCG vaccination and Mantoux test results by year in mm. Results. In the long-term assessment of the phthisiological status of the students with 100% BCG vaccination in childhood, it was recognized as effective in 63.1%, ineffective in 18.3%. In 18.6%, the results did not meet the accepted standards. When evaluating the Mantoux 2 TE sample, MBT infection did not differ in the number and size of papules in all groups. Some students remained sensitive to tuberculin in the presence of a positive Diaskintest, in the absence of data for tuberculosis. Conclusion. Not all common concepts about the criteria for the effectiveness of vaccination fit into the existing rules, some aspects relate to the concept of fuzzy logic. Long-term observations using new methods of immunodiagnostics will allow to solve the issues at a new evidentiary level.