For many people, vaccines trail only clean water on the list of interventions that have had the biggest effect on infectious diseases. Yet with many others fiercely opposed to vaccines, data is needed to support the argument. This week the data arrived, and it makes a strong case for the importance of vaccines.
After scouring health records going back more than 100 years, scientists at the University of Pittsburgh estimate that U.S. childhood vaccine programs have prevented more than 100 million cases of disease. The team reached the figure by looking at reports of cases of 7 major diseases--polio, measles, rubella, mumps, hepatitis A, diphtheria and pertussis--before and after the introduction of vaccines. In each case, the arrival of a vaccine coincided with a falloff in the incidence of disease.
The researchers hope the data will inform the vaccine debate, so at least those opposed to immunization understand the risks. "If you're anti-vaccine, that's the price you pay," Dr. Donald Burke, co-author of The New England Journal of Medicine paper, told The New York Times. The vaccine for diphtheria accounted for almost two-fifths of the prevented cases, in part because it has been used for longer than the other products. Diphtheria was a common disease prevaccination, with 237 cases per 100,000 people per year.
Although the researchers based the NEJM paper on the vaccine data, the implications of their project are much broader. The team digitized more than 100 years of weekly reports on the incidence of notifiable diseases. This data is now available in an open-access database that other researchers can mine. "Rather than have individual groups work on these data depending on restricted data access, that access can now be expanded to the whole world," Dr. Willem van Panhuis said.
Panhuis and his colleagues hope other teams will dig into the data, leading to fresh understanding of how epidemics arise, spread and interact. This, in turn, will lead to more effective use of vaccines and other medical countermeasures.