In addition to novel vaccines, new age groups for which vaccines are recommended have been identified. A new pediatric pneumococcal conjugate vaccine received approval for children under age 2 and high-risk children under age 5 in February 2000 (CDC, 2000d). In 1996, ACIP, AAP, the American Academy of Family Physicians, and the American Medical Association (AMA) jointly recommended immunizing all adolescents aged 11 to 12 with hepatitis B (CDC, 1998b). As mentioned above, ACIP lowered the recommended age for adult influenza vaccination from 65 to 50 years (CDC, 2000a). Many of the vaccines now in the research pipeline will be targeted at adults, and new initiatives will be required to adapt the vaccine delivery system to serve new age groups.
In the next 20 years, the number of vaccines available could triple relative to those recommended today, almost a ninefold increase since the 1950s (when only polio, diphtheria, tetanus, and pertussis vaccines were recommended) (IOM, 1999b) (see Table 2–1). While all of the vaccines that become available may not be recommended for universal use, the schedule’s complexity is certain to increase, although the creation of combination vaccines may minimize the required number of vaccine administrations and office visits.2 Moreover, in addition to the creation of new vaccine types, new forms of administration are being tested, such as the use of live, attenuated influenza virus administered by intranasal spray (Nichol et al., 1999; Poland and Couch, 1999).
With the introduction of new vaccines and changes to the immunization schedule, the cost of vaccination has fluctuated, generally increasing. A majority of new vaccines are considerably more expensive than those used previously. The catalog price for DTP increased from $11.22 in 1987 to $17 for DTaP in 1997, primarily as a result of inflation (Orenstein et al., 1999). In contrast, varicella vaccine has a per-dose catalog price of $45.56, and adolescent hepatitis B costs $20 to $24 per dose (information provided by CDC). The pediatric pneumococcal conjugate vaccine, which will prevent pneumonia, meningitis, and a limited number (about 8 percent) of ear infections, is expected to be relatively expensive, costing about $232 for a four-dose series (Lieu et al., 2000; Stolberg, 2000). In 1987, the combined catalog price for all childhood vaccines was $116; by 1997, the total price had increased to $332–$370 (Orenstein et al., 1999).
The national immunization system is also affected by the changing nature of infectious disease. Pathogens, like human populations, undergo genetic evolution. Such evolution has allowed some viruses to jump from species to species. For example, many scientists believe that smallpox made a trans-species jump into humans between 3,000 and 12,000 years