Hepatitis B virus
(HBV) could be eliminated as a global health threat with a scale-up of
vaccination coverage, enhanced efforts to prevent vertical (mother-to-child) transmission
and expansion of testing and treatment, according to a modelling study
published in The Lancet Infectious Diseases.
With these interventions, incidence of new chronic infections could be reduced
by 90% and mortality rates by two-thirds between 2015 and 2030. HBV-related
mortality could be eliminated in Western Europe as soon as 2017 but it would take
until 2090 to achieve this goal in sub-Saharan Africa. The total cost of the
strategy would be approximately $88 billion, but this would fall if a cure were
“Maintenance of a
business as usual approach will not end the epidemic and will lead to 17
million avoidable deaths over the next 15 years,” comment the authors. “A
comprehensive and ambitious package of interventions that tackle prevention and
treatment could lead to a 90% reduction in incidence of new chronic infections
and a 65% reduction in worldwide mortality by 2030.”
A highly effective
vaccine against HBV exists and antiviral treatment for chronic infection is also
available. Coverage of these interventions is low in some world regions, and
HBV continues to cause approximately 687,000 deaths each year, even though the World Health Organization (WHO)
aspires to the elimination of HBV as a global health threat.
team of investigators therefore developed a model to evaluate the impact of current
public health interventions against HBV, propose targets for reductions in
incidence and mortality, and identify key interventions required to eliminate
the global health threat posed by HBV.
incorporated data on the natural history of the infection, prevalence,
mortality, vaccine coverage, treatment and demographics. The investigators
first estimated the impact of current interventions and examined the effect of their scale up and
the introduction of population-wide screening and treatment.
estimated 850,000 HBV deaths and a global prevalence of 290 million individuals
in 2010, consistent with other epidemiological data. In 2010, 30% of
HBV-related deaths, 70% of new chronic infections and 40% of people living with
the infection were in the five world regions with the most low and middle-income
interventions, the model predicted 4.3 million new chronic infections, 1
million HBV-related deaths and 270 million people living with HBV by 2020.
Between 2020 and
2050, the number of new infections would drop by 70% as a result of sustained
vaccination coverage and there would also be a 40% reduction in the number of
people living with HBV, mainly due to declining incidence and deaths in an
ageing population. The number of HBV-related deaths would increase to 1.14
million per year by 2034 and then decline to 1.06 million per year by 2050.
scale-up has already had a substantial impact on the epidemic. Without any
infant vaccination or birth-dose vaccination, there would be 25 million new
cases by 2020. Therefore, vaccination has already reduced new cases by 83% and
cumulatively prevented 310 million infections between 2010 and 2020.
interventions have not substantially reduced the number of individuals living
with chronic HBV (30% reduction by 2020 vs no interventions) or HBV-related
deaths (4% reduction by 2020 vs no interventions). This lack of progress was
attributed to lack of treatment scale-up.
expansion of interventions, the number of people living with HBV will remain at
the same high levels for up to 50 years. Worldwide, there will be 63 million new chronic infections and 17 million HBV-related deaths between
2015 and 2030.
Scaling up infant
vaccination levels to 90% globally will prevent 4.3 million new infections
between 2015 and 2030 compared to the status quo. Addition of birth-dose
vaccination, and increasing pre-delivery antiviral treatment for mothers with chronic HBV infection to 80% coverage will avert a further 19.3 million new infections.
interventions with 80% coverage will reduce deaths by 65%, preventing 7.3
million deaths between 2015 and 2030.
Half of world
regions will achieve elimination of new chronic infections by 2060 with scale-up
of these interventions. Western Europe could eliminate HBV-related deaths by
2017 but sub-Saharan Africa and Asia would not attain this goal until closer to
The average global
cost of these scaled up interventions will be $5.5 billion annually between
2015 and 2030. Most of the expenditure will be on screening (39%) and treatment
(59%). Costs will peak at $7.5 billion annually but will fall rapidly to $4.7
billion a year in 2030, with further reductions thereafter. The total net cost
will be $88.7 billion by 2030 falling to $84 billion should a cure for HBV be
global approach to tackle HBV – a reliance on infant vaccination – has brought
enormous health gains, but a step-change in strategy will be needed to bring a
target of HBV elimination within reach,” conclude the investigators. “This
change must see a large increase in the proportion of births that benefit from
a package of interventions and in the proportion of people with chronic HBV
carriage who are diagnosed and treated when eligible, as well as maintenance
and expansion of infant vaccination programmes.”