BOX 3-3 Calculating the Size of the Adult Population That Relies on State-Purchased Vaccines No national survey data are available on which to base estimates of the number of privately insured adults between the ages of 18 and 65 who have coverage for immunizations. Consequently, the following estimate of the demand for pneumococcal and influenza vaccines from public health departments is based only on estimates of the uninsured working-age adult population, and does not reflect any low-income underinsured adults, who also may depend on public clinics for free immunizations. ACIP recommends immunization against pneumococcal disease and influenza for adults under age 65 with heart disease, chronic respiratory system conditions, and diabetes, and influenza vaccine for all those age 50 and older. An estimated 11 percent of the population aged 18 through 49 have these conditions, as do an estimated 24 percent of the population aged 50 through 64 (Singleton et al., forthcoming). Applying these risk rates to 26.6 million uninsured adults aged 18 through 49 and 6.2 million uninsured adults aged 50 through 64, respectively, yields a total of 4.4 million at-risk working age adults without health insurance. Adding in all other uninsured persons (those without these chronic conditions) between ages 50 and 65 would double the demand for annual influenza immunizations to 9 million uninsured persons. The public purchase price of influenza vaccine is $2.15 per dose. The annual cost of purchasing vaccines for the groups for which immunization is recommended by ACIP who are uninsured and aged 18 through 64 is thus $19 million. The public purchase price for pneumococcal vaccine is $5.50. The one-time cost of immunizing the 4.4 million at-risk uninsured adults is thus about $24.2 million.