Abstract:
Background: The goal of this study is to evaluate the effectiveness of hepatitis B vaccine and risk factors associated to absence or weak immune response to HBV vaccination among children in Georgia. In the conditions of mass vaccination of hepatitis B, all over the world, including in Georgia, in the vaccinated population, the number of those individuals who could not develop Anti-HBs are growing every day. According to the literature, the main reason for the ineffective vaccination of hepatitis B is considered to be an increase in the prevalence of express mutants among the hepatitis B virus population, which is of a similar intensity throughout the world. In parallel with a detailed analysis of literature sources, the scientific article for the first time studied the seroprevalence of Anti-HBs in the population of Georgian vaccinated children.
Methods: Studies were carried out on 300 vaccinated children. Their age ranged from one month to 17 years. They turned into pediatric clinics for one reason or another, and needed one or another analysis of the venous blood. The study of the seroprevalence of Anti-HBs was carried out by the enzyme immunoassay. In those patients who, after vaccination, could not develop Anti-HBs, HbsAg and HBV concentration were determined by polymerase chain reaction (PCR).
Results: Among 300 immunized children anti-HBs was not developed in 14%. All of them were tested for HBsAg and positive test result was found in only one individual. The study showed that the production of antibodies after hepatitis B vaccination is not influenced by age, gender, or type of disease, because the difference in the data obtained for age or nosological groups is statistically unreliable (P>0.05). By bivariate analysis statistically significant association was found between the development of anti-HBs and ethnicity of a child 87% of children of Georgian ethnicity developed anti HBs vs to 68% of children of other ethnicities; (p<0.05). Besides, higher proportion of children who were immunized on-time according to National Immunization Calendar (90%) developed anti-HBs compared to children whose HBV immunization was postponed (82%) and this association was statistically significant (p<0.05).
Conclusions: According to our Study, it can be noted that the effectiveness of vaccination against hepatitis B virus in Georgia does not differ from other countries of the world. Mutations of the hepatitis B virus and postponing HBV vaccination are considered the main reason for ineffective vaccination.
