To the Editor.
—Dr Margolis and colleagues1 present a logical and detailed cost-effectiveness analysis of various hepatitis B virus (HBV) immunization strategies. They rightly state, "Central to the analysis was an accurate portrayal of the lifetime and age-specific risk of HBV infection in the United States." However, we believe that they have excluded an important contribution from their analyses, namely, the effect of immunization on the risk of infection.Hepatitis B virus is transmitted from person to person. Consequently, protection of one individual by vaccination confers a degree of protection to all others in the population.2 Although for limited immunization coverage this effect is small, it becomes increasingly important as a greater proportion of the population is immunized.Margolis et al compare the expected number of lifetime outcomes in one birth cohort under the various immunization strategies. The underlying assumption is that the probabilities of both infection and disease
Edmunds WJ, Medley GF, Nokes DJ. Cost-effectiveness of Hepatitis B Virus Immunization. JAMA. 1996;275(12):907. doi:10.1001/jama.1996.03530360017018