In 1949, PAHO Director Dr. Fred Soper (seated far right) signs an agreement with the World Health Organization (WHO) making PAHO the Regional Office for the Americas of WHO. Under Soper's energetic leadership, PAHO's budget increased from less than $100,000 in 1947 to $10 million in 1958. Its staff grew from 88 to 750. Soper remained director until 1959.

A lab worker examines blood proteins at the Institute of Nutrition of Central America and Panama (INCAP) in Guatemala City, part of an effort to assess the nutritional status of different population groups. INCAP was one of three international research and training centers established by PAHO during the 1950s. The others were the Pan American Foot-and-Mouth Disease Center (PANAFTOSA) in Brazil and the Pan American Zoonoses Center (CEPANZO) in Argentina.

Participants in the First Conference of Schools of Public Health, held in San Miguel Regla, Mexico, in 1959. This and subsequent PAHO-supported conferences facilitated the exchange of information and experiences about public health education in the Region.

A public health nurse makes home visits in Asunción, Paraguay, in 1952. In the mid-1950s, PAHO adopted a long-term plan for training health workers in the Region and placed new emphasis on preventive and social medicine.

Costa Rican children prepare to receive the BCG vaccine for tuberculosis in 1952. By the mid-1950s, vaccines were available against TB, diphtheria, influenza, pertussis, polio, smallpox, and tetanus. PAHO supported member countries' efforts to carry out immunization campaigns.

Members of a health statistics team in Port-au-Prince, Haiti, during the 1950s. Their section chief (standing, right) received training through a PAHO fellowship at the Inter-American Center of Biostatistics in Santiago, Chile.