On Apr. 6, 1977, the Department of Health, Education, and Welfare (now Department of Health and Human Services) announced a nationwide Childhood Immunization Initiative.

The Initiative had two stated objectives: 1) To attain immunization levels in the nation’s children of at least 90% by October 1979; and  2) To establish mechanisms to maintain high immunization levels by ensuring that children received vaccinations at the proper times.

In 1977, approximately 20 million of the 50 million persons in the United States who were 15 years old were estimated to need at least 1 dose of 1 vaccine in order to be considered fully protected against the 7 diseases for which vaccines are routinely administered in childhood–i.e., diphtheria, measles, mumps, pertussis, poliomyelitis, rubella, and tetanus.