The University of Pittsburgh Graduate School of Public Health has examined over 100 years of health records to compile a very interesting and compelling study that supports vaccination efforts. The study, “Contagious Diseases in the United States from 1888 to the Present,” was published in the New England Journal of Medicine and focuses on comparing pre-vaccine health records with post-vaccine health records for seven major diseases, including polio, measles, rubella, mumps, hepatitis A, diphtheria and pertussis (whooping cough). By looking at the pre-vaccine data, they were able to project the number of cases that would have occurred if the vaccine had not been invented. Using this method they estimate that U.S. childhood vaccine programs have prevented more than 100 million cases of disease.
Death rates weren’t included in the study because of the inaccuracy of death certificates in the early portion of the study years. However in the New York Times Article, “The Vaccination Effect: 100 Million Cases of Contagious Disease Prevented,” “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 three million to four million”.
The work was a major undertaking with over 100 years of public health records, most from the Center for Disease Control’s weekly morbidity reports that had to be entered into a database system where the data could then be analyzed. While the paper only covers 7 major diseases, researchers looked at 56 diseases in total. All of the data is now available in a database for the public. The hope is that researchers can use this information to look at many different aspects of vaccination programs including how outbreaks spread, impact of vaccinations and historical epidemics. The data is available at Project TYCHO Data for Health. The study was funded by the National Institutes of Health and the Bill and Melinda Gates Foundation.
An important note to consider is that the estimate of 100 million diseases prevented does not include other serious diseases that cause illness and death that we have vaccines for including influenza, rabies, chicken pox, and small pox, just to name a few. These diseases and many more are included in the 56 diseases researched by the University of Pittsburgh team and more information about each is available on the Project TYCHO website. In a recent blog titled, “Innovators who paved the way for modern vaccines,” we covered the discovery of some of the most influential vaccines and the innovators who discovered them.
Perhaps this new data will provide a valuable resource when informing the vaccination debate. As an increasing number of parents opt out of vaccinating their children based on fears about vaccines, the rates of some of the serious diseases included in the report are on the rise. These new outbreaks include recent outbreaks of measles, mumps and whooping cough. It is important that misinformation be corrected and that the importance and safety of vaccines be presented to the public. This issue was raised in our recent Ask the Expert, “Vaccines, an interesting discussion of vaccines past, present and future,” hosted by Paul A. Offit, MD, the Chief of the Division of Infectious Diseases and the Director of the Vaccine Education Center at the Children’s Hospital of Philadelphia and author of several vaccine related books. A question was asked in our discussion – What do you think were the biggest factors that led to the anti-vaccine movement and what can we do to change public perception and assure safety? Dr. Offit’s answer below addresses the issue of educating the public and making the data compelling.
Regarding the first part of your question, I think that the single greatest factor that led to an anti-vaccine backlash (which began in the early 1800s in response to the smallpox vaccine) was vaccine mandates. I think if you ask the professional anti-vaccine groups what would cause them to stop their activities they would say to make vaccines optional. This, of course, would be a disaster for society as it would no doubt lead to an erosion of vaccine rates and an increase in vaccine-preventable diseases.
Regarding the second part of your question, I would argue that vaccines are the safest, best tested medical products that we put into our bodies. So the issue isn’t one of data (plenty of data are available to address these concerns). The issue is one of making those data compelling. And that is where I think we have fallen short. We have to be able to grab the attention of the media and the public with the data that can exonerate vaccine fears.
Hopefully this new data can be presented in a way in which the public can grasp the power of vaccines and the potential for these diseases to reemerge without proper vaccinations.