When the possibilities for disease prevention are endless, challenges are close behind

November 1, 2005

We're learning that the possibilities for prevention of disease through vaccines are farther-reaching than we imagined during the last century.

A familiar and gratifying story can be read in graphs that demonstrate a marked decline in, or the disappearance of, infectious diseases prevented by recommended childhood immunizations. During the past five or six decades, one dreaded infection after another has been demonstrated to be preventable and (in countries willing and able to provide vaccines) has been prevented. Diphtheria, polio, measles, bacterial meningitis-all were feared and all have been defeated or diminished.

New vaccines-licensed or in development-pose difficult challenges for policy makers, however, as well as a difficult question: How much are we willing to pay for potential improvements in child health? It is possible, after all, that a recommendation for routine hepatitis A vaccination of all US children and for routine use of a new rotavirus vaccine could enhance the general health of children and reduce absences from child-care, school, and work. And routine use of the conjugated meningococcal vaccine in infants (if the US Food and Drug Administration licenses the vaccine for that age group) could further reduce the incidence of invasive Neisseria meningitidis infection.

That isn't all. There are now two vaccines likely to prevent not only the infectious disease against which they are targeted but the cancer that can result from long-term infection. Hepatitis B vaccine has already substantially reduced the incidence of hepatitis B infection and carriage in the United States and elsewhere; over time, that reduction should also lead to a decline in the incidence of hepatocellular carcinoma. A human papillomavirus vaccine is likely to be licensed and recommended within 12 months, offering the potential to prevent at least 70% of cases of cervical cancer that would otherwise develop.

We're learning that the possibilities for prevention of disease through vaccines are, if not endless, at least farther-reaching than we imagined during most of the last century. Decisions about how best to use those vaccines-on whom and when, and at what cost-will challenge our ethical principles even more than they challenge our pocketbooks.