Children will always hate shots, but a recent study published by two Harvard School of Public Health professors shows that they may be good for more than just their health—children in developing countries who receive regular immunizations may also earn more during their adult lives.

In the study, researchers concluded that immunization programs can help boost the economies of developing countries and that the international community should recognize these added benefits.

“There is a strong case, therefore, for a renewed international commitment to vaccination,” the study, which was published in World Economics, says.

Authors David E. Bloom, Gamble professor of economics and demography, David Canning, professor of economics and international health and Marc Weston of River Path Associates in the United Kingdom, found that previous studies on the subject of immunization focused primarily on the benefits to physical health but failed to quantify the programs’ economic impact.

“The long-term productivity effects of immunization that we estimate are in addition to the direct health benefits in the form of reduced infant mortality and illness,” Canning said.

The model proposed in the study added childhood health as a component of the capital variable in the production function. As a result, vaccination efforts, in addition to improving health, spurred long-term economic growth through increased productivity.

The first part of the study analyzed the economics rates of return on immunizations using the Global Alliance for Vaccines and Immunization’s (GAVI) standards.

“Our work suggests a very high return to child health investments as a form of human capital that, like education, increases worker productivity,” Canning said.

According to the study, the rate of return on investments in immunization in developing countries is 12.4 percent for 2005. Because vaccination costs are predicted to decline, the authors of the study posited that returns on investments will increase to 18 percent by 2020.

The study predicted that children born in developing countries in 2005 who participate in the immunization program will earn 0.78 percent higher wages than children who do not. By 2020 the wage discrepancy will increase to 2.39 percent.

“By boosting cognitive abilities, [the immunization program] improves children’s prospects of success when reaching working age. And it does so in an extremely cost-beneficial way,” the study states. “Immunization provides a large return on a small investment—higher than most other health interventions, and at least as high as non-health development interventions such as education.”

The second part of the study examined children in the Philippines born between 1983 and 1984. It compared the IQs of 1,975 children who participated in the Cebu Longitudinal Health and Nutrition Survey (CLHNS), and compared the performance of those who were immunized against those who were not.

The immunized group of children were inoculated against polio, measles, tuberculosis, and DTP within the first two years of their lives. The second group never received vaccinations.

The study found that vaccinations during childhood resulted in substantially higher IQs as well as higher language and math test scores when compared with their non-immunized counterparts.

The results of this study come as the international community announced the International Finance Facility for Immunization (IFFIm). Through this new vehicle, several countries, including the United Kingdom, France, Italy, Spain, and Sweden pledged to increase GAVI’s efforts in the next ten years and have already guaranteed $4 billion.

“The benefits of a push for increased immunization are likely to heavily outweigh the costs, and policy makers who neglect immunization will be missing a great opportunity for promoting development,” the study said.

—Staff writer Giselle Barcia can be reached at gbarcia@fas.harvard.edu.