c.2013 New York Times News Service

c.2013 New York Times News Service

Vaccination programs for children have prevented more than 100 million cases of serious contagious disease in the U.S. since 1924, according to a new study published in The New England Journal of Medicine.

The research, led by scientists at the University of Pittsburgh’s graduate school of public health, analyzed public health reports going back to the 19th century. The reports covered 56 diseases, but the article in the journal focused on seven: polio, measles, rubella, mumps, hepatitis A, diphtheria and pertussis, or whooping cough.

Researchers analyzed disease reports before and after the times when vaccines became commercially available. Put simply, the estimates for prevented cases came from the falloff in disease reports after vaccines were licensed and widely available. The researchers projected the number of cases that would have occurred had the pre-vaccination patterns continued as the nation’s population increased.

The journal article is one example of the kind of analysis that can be done when enormous data sets are built and mined. The project, which started in 2009, required assembling 88 million reports of individual cases of disease, much of it from the weekly morbidity reports in the library of the Centers for Disease Control and Prevention. Then the reports had to be converted to digital formats.

The University of Pittsburgh researchers also looked at death rates, but decided against including an estimate in the journal article, largely because death certificate data became more reliable and consistent only in the 1960s, the researchers said.

But Dr. Donald S. Burke, the dean of Pittsburgh’s graduate school of public health and an author of the medical journal article, said that a reasonable projection of prevented deaths based on known mortality rates in the disease categories would be 3 million to 4 million.

The scientists said their research should help inform the debate on the risks and benefits of vaccinating U.S. children.

Pointing to the research results, Burke said, “If you’re anti-vaccine, that’s the price you pay.”

The medical journal article notes the recent resurgence of some diseases as some parents have resisted vaccinating their children. For example, the worst whooping cough epidemic since 1959 occurred last year, with more than 38,000 reported cases nationwide.

The disease data is on the project’s website, available for use by other researchers, students, the news media and members of the public who may be curious about the outbreak and spread of a particular disease.