Abstract and Introduction
Background: Universal vaccination of newborns with hepatitis B virus (HBV) vaccine is the most important strategy to prevent chronic HBV infection and its complications of which hepatocellular carcinoma (HCC) as the deadliest.
Aims: To evaluate the impact of universal HBV vaccination on the prevalence of chronic HBV infection, and the incidences of HCC and hepatic events in young adults born before and after the introduction of the universal HBV vaccination programme in 1988 in Hong Kong
Methods: This was a territory-wide retrospective observational cohort study of consecutive adult subjects born in 1970–2002 with hepatitis B surface antigen (HBsAg) checked. Subjects born during the vaccination era (1988–2002) were included in the vaccinated cohort; subjects born between 1970 and 1987 were included in the unvaccinated cohort.
Results: We included 695,925 subjects for HBV prevalence analysis. Chronic HBV infection dropped from 14.3% in subjects born in 1970, to 6.7% in subjects born in 1988. In total, 53,960 vaccinated and 318,290 unvaccinated subjects who had available clinical data were included for event analysis. HCC and hepatic events occurred in 44 (0.1%) and 75 (0.1%) of the vaccinated subjects and in 1305 (0.4%) and 1806 (0.6%) of the unvaccinated subjects, respectively. All incidence rates remained numerically lower in vaccinated subjects after adjustment for age, gender and antiviral treatment, but failed to reach statistical significance due to very low incidence rates.
Conclusions: Universal HBV vaccination markedly reduces the prevalence of chronic HBV infection and may contribute to the decreased incidences of HCC and hepatic events.
World Health Organisation (WHO) published the first global health sector strategy on viral hepatitis in June 2016, a strategy that contributes to the proposed targets for the reduction of chronic viral hepatitis incidence and mortality of 90% and 65%, respectively, by 2030. In Hong Kong, the Chief Executive's 2017 Policy Address asked to set up the Steering Committee to formulate strategies to effectively prevent and control viral hepatitis. The Steering Committee is currently reviewing local and international trends and developments in the prevention and control of viral hepatitis; advising the Government on policies and cost-effective targeted strategies for prevention and control of viral hepatitis and conducting and coordinating the surveillance and evaluation of viral hepatitis control and recommend appropriate response. Therefore, a comprehensive review of the disease burden of chronic hepatitis B virus (HBV) infection would provide pivotal data to the Government and the Steering Committee to guide the strategies to achieve the goals set by WHO.
Universal HBV vaccination for all newborns is the most important strategy to prevent chronic HBV infection. Hong Kong has adopted a universal vaccination for all newborns since 1988, which has led to a marked decline in the prevalence of chronic HBV infection in children and young adults. HBV vaccination is also recommended for adults at high risk of chronic HBV infection. However, in the presence of the constant immigrants from other parts of the world, the prevalence of chronic HBV infection has remained static at approximately 6% over the past few years.
From now, nations have eight more years to reach the WHO goals by 2030. At this critical moment to work towards these goals, we aimed to assess the viability of HBV elimination through the universal HBV vaccination programme in Hong Kong, specifically to evaluate the impact of universal HBV vaccination on the prevalence of chronic HBV infection, and various important clinical events namely hepatocellular carcinoma (HCC), and hepatic events in young adults born in or after 1988.
Aliment Pharmacol Ther. 2022;56(5):869-877. © 2022 Blackwell Publishing