In 1992, the World Health Organization recommended vaccinating all newborns and children aged < 12 months, along with adolescents, for hepatitis B virus (HBV). Russia was one of the countries that took that recommendation to heart, beginning a mass immunization program in 1997. The progtam started with newborns, added adolescents in 2001, and included adults nationwide in 2006. Children aged < 12 months are now vaccinated in 3 doses: the first within 24 hours of birth with additional boosters at 1 and 6 months.
To gauge its success, researchers from Chumakov Institute of Poliomyelitis and Viral Encephalitides, Moscow, and The Ministry of Health of the Russian Federation collected sera samples from volunteers in 6 geographically distant and epidemiologically different regions of Russia. They used a mathematical model developed by the CDC to estimate the effects of vaccination and birth dose coverage on the incidence of HBV. Hepatitis B virus DNA was detected in 63 sera samples.
Between 1993 and 1996, infection rates had risen from 22.4 per 100,000 people to 40 per 100,000. Following the initiation of the mass HBV vaccination program, the researchers say the number of acute HBV cases dropped by more than 33-fold, to 1.3 per 100,000 in 2014.
Still, they note, the incidence of chronic hepatitis—down only to 11.3 per 100,000 in 2014, from 14.2 per 100,000 in 2008—remains a source of concern, indicating “a persistent, substantial reservoir of the infection.”
Based on the reported data on vaccination of newborns, the number of expected acute and chronic HBV cases in the study generation (children born in 2008) can be reduced as much as 19-fold, the researchers say. They estimate that vaccination prevents 91% to 95% of cases of HBV that would otherwise occur. Timely vaccination also can reduce the estimated number of HBV-associated deaths by nearly 19-fold, they say.
Despite the substantial reduction in the incidence of acute HBV, though, the epidemic in Russia remains serious, the researchers say. However, they add, the low prevalence of HBV immune escape mutants 10 years after the mass vaccination began bodes well for the program’s future effectiveness.
Klushkina VV, Kyuregyan KK, Kozhanova TV, et al. PLoS ONE. 2016;11(6):e0157161.