Post-vaccination humoral immunity against viral hepatitis B of healthcare workers in Republic of Tatarstan

Introduction . Immunization against viral hepatitis B is the most effective method of preventing this disease. In 1996 immunization against hepatitis B of medical workers began in the Republic of Tatarstan. However, studies on the duration, level of post-vaccination immunity and the effectiveness of vaccination against hepatitis B of healthcare workers have not been conducted. The purpose of the study is to find out the duration and level of post-vaccination immunity against hepatitis B of healthcare workers of the Republic of Tatarstan and evaluation of the immunological efficacy of vaccination. Materials and methods. The study was conducted on the blood serums of the healthcare workers vaccinated against hepatitis B in 5 medical organizations of the Republic of Tatarstan. The period starting from vaccination and ending with examination lasted from 1 to 17 years. The ELISA method (commercial test-systems of companies «Bio-Rad» and «Vector-Bes») was used for detection of hepatitis B markers in the blood serums of healthcare workers. During the dynamic examination, anti-HBc-antibodies also were determined in the blood serums. Results . The study of post-vaccination immunity level against viral hepatitis B of 412 healthcare workers in the Republic of Tatarstanhas shown that immunization against this type of infection provides long-lasting intense immunity of vaccinated people in 51,7% of cases. The frequency of detection of anti-HBc-antibodies remains at the same level (24,1%) against the background of the absence of a surface antigen, which indicates the absence of a latent infection. The duration of circulation of high titers of antibodies depends on the age of people at the start of vaccination. According to the results of the serological examination of vaccinated people, decrease of the level of post-vaccination immunity is observed after 5 years from the moment of vaccination. Conclusion. The absence of a manifest case of disease or infection with the hepatitis B virus of the healthcare workers who had a full course of vaccination against hepatitis B, indicate the effectiveness of immunization. The reduction of immunity level of vaccinated healthcare workers necessitates revaccination against viral hepatitis B after 5 years from the moment of vaccination