ters are especially important to meet school entry requirements for young children and to address the health needs of recent immigrants.

• The appearance of new vaccines offering valuable and long-awaited protection from additional infectious diseases has caused states to draw on Section 317 funds during transitional periods. This situation occurred, for example, during the 11-month period after ACIP recommended the varicella vaccine and before a federal purchase contract was negotiated.

States vary in the way they respond to their residual needs. A few states rely solely on federal support, since all of the vaccines provided through their public health clinics are financed by Section 317. Others have used state revenues to purchase additional vaccines to meet their residual needs. States have broad discretion in determining whether to use state or federal funds to purchase vaccines, hire staff, or support contractual efforts. Some states use internal funds for personnel and thus rely more heavily on federal vaccine purchases; others draw on federal employees where possible to staff their immunization programs, and reserve their own funds for vaccine purchases and other programmatic needs.

State investments in immunization services appear to have increased during the 1990s, but these increases have not been at the same dramatic levels seen with the creation of VFC or the early growth in Section 317 budgets. States were more likely to extend their efforts through their investments in expanded Medicaid coverage, both by increasing vaccine administration fees and by broadening the base of clients served by Medicaid plans. Evidence is not available to indicate how the states invested in other types of immunization programs during this period.