The committee discussed barriers in addition to those identified above in the section on R&D. Vaccine delivery poses significant barriers to the effective prevention and control of infectious disease. Children in the United States can receive up to 16 injections and three oral doses of vaccine delivered against 8 infectious diseases before the age of 2 years. The rate of compliance with the recommended immunizations at 2 years of age is below that achieved for children a few years older due to compliance with vaccination requirements for school entry. Combination vaccines promise to reduce the number of vaccine doses that must be administered separately, but these will not be a panacea. The combinations will help to increase the level of acceptance and the rates of utilization of vaccines, but clinical trial design issues are not trivial. The committee hopes that the Federal government and state governments, the medical community, the public, and vaccine manufacturers carefully think about rational approaches to combination vaccines and vaccination schedules. Furthermore, noninjection routes of delivery (for example, oral, intranasal, or cutaneous routes of delivery) should receive serious consideration. At the same time, the committee knows that market forces and corporate alliances will influence the availability of combination products.

Despite the impediments of delivering so many immunizations during infancy, mandatory childhood immunization is a fundamental part of health care for children in the United States. Adolescents and adults have received less information about the importance of vaccines to protect their health and are less accessible than children to health care providers, especially for preventive health care services. Patient and provider education about the benefits of new vaccines will be crucial.

Vaccines are one of the few preventive measures that save money. It is not clear that people are willing to accept, use, and pay for vaccines that do not save money. For example, it is the opportunity cost savings for a parent who does not need to take time off from work to care for a sick child that has helped make the varicella-zoster virus vaccine a marketable preventive health intervention. Saving a child from illness and the very rare cases of death due to chicken pox was not enough to convince some in the medical establishment and some parents that the varicella-zoster virus vaccine was important.

The model described in this report demonstrates that not all vaccines will save money. Some new vaccines might be very expensive. However, the health benefits might still be compelling. Use of these vaccines will require a shift in thinking from an expectation that vaccines always save money to an acknowledgment that the health benefits of some vaccines might be worth the cost.

Many vaccines are not covered by health insurance, under either indemnity plans or managed care plans. Financial incentives might be crucial for encouraging the use of vaccines. The Vaccines for Children Program and other public health initiatives have helped provide childhood vaccines to those who can not afford them. Federal and state governments need to prepare now to work with