Because the RF's first public health campaign in Mexico had been funded and organized on a scale both to satisfy the RF's larger yellow fever eradication ambitions and to woo its hard-to-get Mexican counterpart, it was the campaign that followed yellow fever that would better define the terms of the relationship. At the most pragmatic level, the IHB's stock campaign against hookworm disease offered a compromise collaboration. It would both keep the RF in Mexico at a lower expense and extend the reach of the DSP, albeit for an ailment that was not a high epidemiologic priority. The claims on Mexico's federal government stemming from the revolution demanded far more public health infrastructure than the hookworm campaign could provide, yet the campaign's very existence in a key region served as a powerful demonstration of the institutionalization of health services to come.

In locating the campaign in and around Veracruz, where unrest continued to threaten Mexico City, the Mexican government and the RF shared the view that popular public health efforts could help stabilize the region. As during the yellow fever campaign, the IHB sought to play both sides against the middle, courting Mexico City officials and Veracruz leaders at the same time. The DSP made use of the IHB campaign to heighten its presence in Veracruz during a politically thorny period, distancing itself from the RF as necessary. This was a dangerous game for all parties, and the RF-Mexico collaboration at times seemed to be tempting fate.

The hookworm agreement sought to establish a balance of power between the DSP and the IHB, in which the IHB maintained the upper hand in the selection of the disease and in decisions over the financial obligations of all parties. In addition, RF officers were given considerable latitude in day-to-day operations, even when the campaign faced controversy over treatment regimes and preventive measures.

But the DSP was no tabula rasa waiting to be inscribed upon from afar. At the time when arrangements for a new cooperative endeavor were being crafted in 1922–23, the DSP was expanding its role in areas such as health education, child hygiene, and professional training.