Regional variation in the cost effectiveness of childhood hepatitis A immunization. Jacobs RJ, Greenberg DP, Koff RS, Saab S, and Meyerhoff AS. The Pediatric Infectious Disease Journal 2003;22(10):904-914
Explanatory note: With steadily improving sanitation and food processing, rates of hepatitis A have been decreasing in the U.S. However, there are wide variations in rates of hepatitis A across the U.S. (highest in the West, lowest in the North East). Hepatitis A is often asymptomatic (causes no symptoms) in young children. Nevertheless, adolescents and adults may become sick. Although most recover, a small proportion develops liver failure.
An inactivated hepatitis A vaccine was licensed in 1995 and has been recommended for use in children over 2 years of age, in areas of the U.S. with the highest risk of the disease. It has been recommended to protect the older child from developing hepatitis A but also to reduce spread to family and other close contacts (for example, classmates).
What would be the costs and benefits of universal recommendation of hepatitis A immunization of healthy U.S. children 2 years of age and older in regions with varying hepatitis A incidences (numbers of new cases)?
This study developed a model to estimate the costs and benefits of extending hepatitis A immunization recommendations to regions with lower incidences of the disease than those where it is presently routinely recommended (200% or more the national average).
The researchers divided states into four groups, according to their hepatitis A incidence compared to the national average: 200% or more (11 states), 100 to 199% (6 states), 50 to 99% (16) and less than 50% (18).
They then considered what would happen if all the persons born in 2000 had been immunized against hepatitis A at 2 years of age. They sought to estimate vaccination costs, savings from reduced medical interventions and work loss, longevity gains and quality of life improvement.
In the region with disease rates of 200% or more the national average, immunization would save $35 million in combined medical and work loss costs, and provide more than 3000 quality-adjusted life years (QALYs).
“Expanding immunization to the region with disease rates of 100 to 199% the national average would also reduce costs and improve health outcomes,” the researchers wrote. “Further expansion to the region with disease rates of 50 to 99% of the national average would cost $13 800 per QALY gained.”
In the regions with disease rates less than 50% the national average, routine hepatitis A immunization would be less cost effective.
Childhood hepatitis A vaccination is most cost-effective in areas with the highest incidence rates but would also meet accepted standards of economic efficiency in most of the US. An immunization extended to the entire country would prevent substantial morbidity and mortality, with cost effectiveness similar to that of other childhood immunizations.
Cost effectiveness models such as this are often used to estimate the potential impacts of various immunization strategies. Such models are subject to how accurate the assumptions are.
Many childhood vaccines are cost saving, such as hepatitis A in the Western U.S. In other areas in the U.S., the cost effectiveness of the vaccine might be expected to be similar to other health maintenance strategies, such as bicycle helmets.