and seven years of age across the Sverdlovsk region was introduced in 2003. During the course of this vaccination programme there was a reduction in HAV incidence in the general population, from 47 cases/100,000/year in 2003 to 2.8 cases/100,000/year in 2009, that subsequently prompted a reduction in the age of immunisation to 20–30 months.77
A HAV vaccination programme was initiated in Minsk City, Belarus, in 2003 in response to an apparent epidemiological shift to increased infection risk in children and young adults.73,78
Prior to the start of mass
immunisation, HAV incidence rates varied considerably due to frequent cyclic outbreaks, but between 2000 and 2002 the overall incidence was 38 cases/100,000/year.78
Following the universal
immunisation of children six years of age with vaccine uptake >98%, no cases were observed in the vaccinated population and the incidence in the general population decreased to five cases/100,000/year in 2006, indicating a herd immunity effect.78 However, an outbreak in 2006 with asymptomatic children below six years of age as the attributed source highlights the need to begin immunisation at the earliest age possible.
Cost-effectiveness of Universal Childhood Immunisation Programmes for Hepatitis A Prior to the implementation of any immunisation programme the cost of vaccination should be offset by the subsequent reduction in burden of disease costs, including medical costs, loss of productivity and expenditure for disease control.79
demonstrate cost-effectiveness that is similar to universal vaccination programmes for other diseases and even cost-benefit.79 Importantly, when herd immunity is considered, cost-effectiveness improves further.84
immunisation programmes for hepatitis A in countries of medium to high socioeconomic status, including the US,79,80 and Israel,83
Canada,81 Germany82 However, in countries of intermediate
socioeconomic status, additional costs may have to be taken into account, including a general lack of healthcare resources, the possible lack of infrastructure for delivery of the vaccine and competing healthcare problems. Despite this, the cost-effectiveness of universal childhood HAV vaccination has been demonstrated in countries including Argentina,85,86 other countries.91,92
China,87 Brazil88 and Chile,89,90 but not Cost-effectiveness may also be improved if
hepatitis A vaccine can be co-administered or combined with another vaccine at pre-existing vaccination visits, depending on existing schedules, if a single dose of HAV vaccine can be shown to be as
1. Wasley A, Fiore A, Bell BP, Hepatitis A in the era of vaccination, Epidemiol Rev, 2006;28:101–11.
2. Jacobsen KH, Wiersma ST, Hepatitis A virus seroprevalence by age and world region, 1990 and 2005, Vaccine, 2010;28:6653–7.
3. Jacobsen KH, Koopman JS, The effects of socioeconomic development on worldwide hepatitis A virus seroprevalence patterns, Int J Epidemiol, 2005;34:600–9.
4. Koff RS, Hepatitis A, Lancet, 1998;351:1643–9. 5. Cuthbert JA, Hepatitis A: old and new, Clin Microbiol Rev, 2001;14:38–58.
6. Fiore AE, Wasley A, Bell BP, Prevention of hepatitis A through active or passive immunisation: recommendations of the Advisory Committee on Immunisation Practices (ACIP), MMWR Recomm Rep, 2006;55:1–23.
7. Nothdurft HD, Hepatitis A vaccines, Expert Rev Vaccines, 2008;7:535–45.
8. Bell BP, Hepatitis A vaccine, Semin Pediatr Infect Dis, 2002;13:165–73.
9. Van Damme P, Banatvala J, Fay O, et al., Hepatitis A booster vaccination: is there a need?, Lancet, 2003;362:1065–71.
10. Franco E, Giambi C, Ialacci R, et al., Risk groups for hepatitis A virus infection, Vaccine, 2003;21:2224–33.
effective as the two-dose standard and when the true extent of long- term protection is determined.
Summary and Conclusions
Hepatitis A epidemiology shows large heterogeneity between, and sometimes even within, countries. Socioeconomic development is associated with shifts in hepatitis A epidemiology from higher to intermediate and lower endemicity levels. Asymptomatic children are often a sizeable and largely unrecognised source of HAV transmission; preventative strategies based only on immunising high-risk groups and/or offering post-exposure prophylaxis cannot control HAV at the population level in such settings. Hepatitis A vaccines are widely available, highly immunogenic and effective in pre-exposure and post- exposure prophylaxis, have an excellent safety profile and a flexible dosing schedule and offer long-lasting immunity in almost all vaccinated people. In light of this, universal childhood immunisation represents a strategy worth considering for the prevention of HAV. Evidence from existing universal childhood vaccination programmes is accumulating, and consistently shows that they are effective both on a regional and nationwide scale even when vaccine uptake is incomplete or only a single dose of vaccine is used, and provide both direct and indirect immunity. Moreover, universal childhood vaccination can cause a shift in epidemiology from one of frequent, cyclic, often severe community-wide outbreaks to sporadic cases only.
The WHO does not recommend mass childhood vaccination in areas of high endemicity since exposure to HAV is widespread during childhood, resulting in lifelong immunity.48
vaccination programmes are not recommended in areas of low endemicity and current WHO policy recommends the targeting of high-risk groups only, although arguments in favour of universal vaccination in these areas have been made.93,94
In areas of intermediate
endemicity, and especially in those in transition where increasingly large populations of adolescents and adults are susceptible to HAV infection, the WHO recommends the consideration of universal childhood vaccination.48
However, since these areas are generally of
intermediate socioeconomic status there may be significant obstacles to the introduction of vaccination. Furthermore, other issues remain when adopting a universal childhood immunisation strategy including the age at which vaccination begins95
and the fact that individuals are
Nonetheless, the initiation of universal childhood vaccination most likely represents an attractive option for controlling the global prevalence of hepatitis A disease. n
still at risk of infection when travelling to areas of high or intermediate endemicity.96
11. Hendrickx G, Van Herck K, Vorsters A, et al., Has the time come to control hepatitis A globally? Matching prevention to the changing epidemiology, J Viral Hepat, 2008;15:1–15.
12. Cotter SM, Sansom S, Long T, et al., Outbreak of hepatitis A among men who have sex with men: implications for hepatitis A vaccination strategies, J Infect Dis, 2003;187:1235–40.
13. Spada E, Genovese D, Tosti ME, et al., An outbreak of hepatitis A virus infection with a high case-fatality rate among injecting drug users, J Hepatol, 2005;43:958–64.
14. Wheeler C, Vogt TM, Armstrong GL, et al., An outbreak of hepatitis A associated with green onions, N Engl J Med, 2005;353:890–7.
15. Luyten J, Beutels P, Costing infectious disease outbreaks for economic evaluation: a review for hepatitis A, Pharmacoeconomics, 2009;27:379–89.
16. Ambrosch F, Wiedermann G, Jonas S, et al., Immunogenicity and protectivity of a new liposomal hepatitis A vaccine, Vaccine, 1997;15:1209–13.
17. Van Damme P, Van Herck K, A review of the efficacy, immunogenicity and tolerability of a combined hepatitis A and B vaccine, Expert Rev Vaccines, 2004;3:249-–67.
18. Vidor E, Fritzell B, Plotkin S, Clinical development of a new inactivated hepatitis A vaccine, Infection, 1996;24:447–58.
19. Jiang W-P, Chen J-T, Wang X, et al., Immunogenicity and safety of three consecutive lots of a new preservative-free inactivated hepatitis A vaccine (Healive®): a double-blind, randomized and controlled trial, Vaccine, 2008;26:2297–301.
20. Beeching NJ, Clarke PD, Kitchin NRE, et al., Comparison of two combined vaccines against typhoid fever and hepatitis A in healthy adults, Vaccine, 2004;23:29–35.
21. Mao JS, Chai SA, Xie RY, et al., Further evaluation of the safety and protective efficacy of live attenuated hepatitis A vaccine (H2-strain) in humans, Vaccine, 1997;15:944–7.
22. Bell BP, Negus S, Fiore AE, et al., Immunogenicity of an inactivated hepatitis A vaccine in infants and young children, Pediatr Infect Dis J, 2007;26:116–22.
23. Letson GW, Shapiro CN, Kuehn D, et al., Effect of maternal antibody on immunogenicity of hepatitis A vaccine in infants, J Pediatr, 2004;144:327–32.
24. Lee SD, Chan CY, Yu MI, et al., Safety and immunogenicity of inactivated hepatitis A vaccine in patients with chronic liver disease, J Med Virol, 1997;52:215–8.
25. Reuman PD, Kubilis P, Hurni W, et al., The effect of age and weight on the response to formalin inactivated, alum-adjuvanted hepatitis A vaccine in healthy adults,
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