INVESTIGATION OF THE SPREAD OF A VACCINE-INDUCED ESCAPE MUTANT OF HEPATITIS B VIRUS, BY USING A COMPUTER-BASED EPIDEMIOLOGICAL MODEL

Objective. To investigate the spread of vaccine-induced escape mutant variants of hepatitis B virus (HBV), by using a developed computer-based model. Materials and methods. The authors used the data available in the scientific literature on the current clinical and epidemiological features of hepatitis B (HB), the results of long-term retrospective epidemiological analysis of HB morbidity rates, and the data on the achieved scopes of HB vaccination among the Russian Federation’s population. The HB epidemic process model was based on the Baroyan-Rvachev mathematical epidemic modeling theory. The mathematical HB epidemic process as a computer-based HBV-escapemut program was accomplished by the computer-based EpidMod for Windows modeling technology developed at the N. F. Gamaleya Research Institute of Epidemiology and Microbiology, Ministry of Health of Russia. Results. The preliminary results of computer-based experiments using the model have shown that there is presently a potential accumulation for the spread of HBsAg-mutant variants in Russia: the incidence of acute HB infection caused by mutant variants will be low and insignif icantly higher over more than 40-50years, after which the incidence of acute HB may show a pronounced rise and a peak. The spread rate and intensity of HBsAg-mutant variants are influenced by a number of parameters: the probability of their emergence in patients with chronic HB; the number of people with prior HB infection caused by wild-type virus and with a risk for infection with HBsAg-mutant variants; and the scope of wild-type HB infection vaccination in the population. Conclusion. The prediction results establish the need to design new-generation recombinant vaccines inducing protective immunity against both wild-type and HBsAg-mutant variants in order to prevent their spread. Sanitary and education work on HB prevention is of no small importance to a target group (aged 15-40 years), particularly to people at risk for infection with an HBsAg-mutant variant.

hepatitis B, epidemic process, vaccine-induced escape mutant variants, mathematical model, computer-based experiments