Vaccinations save an estimated 6 million to 9 million lives worldwide each year and have decreased most vaccine-preventable childhood diseases by more than 95 percent in the United States, according to a 2013 report by the Center for American Progress. However, a significant number of children in the U.S. are currently unvaccinated, despite state vaccination mandates for schoolchildren, as a result of a growing number of nonmedical exemptions.
Vaccines are an effective means of eliminating outbreaks of vaccine-preventable diseases, not only because they protect the individuals who are vaccinated, but because they also offer community-wide protection by establishing "herd immunity." While rates vary for each type of vaccine, when about 80 to 85 percent of a given population is properly vaccination, the likelihood that a susceptible person will come into contact with an infected person is reduced, ultimately decreasing the chances that the community will experience a disease outbreak, according to the report.
However, the rise of vaccine exemptions has increased the risk of infectious disease outbreaks, especially among children, the report says. As a result, herd immunity is being eliminated and the rate of infectious disease outbreaks has increased.
The Center for American Progress analyzed research on state childhood vaccination mandates and exemption categories to understand the role nonmedical exemptions play in reducing immunization coverage in communities across the United States. Findings from the report are listed below.
- Every state except Mississippi and West Virginia grants some kind of religious exemption from vaccination, and 17 states allow for "personal belief" or philosophical exemptions.
- Within-state variance exists for granting nonmedical exemptions. For example, in 2005, 18.1 percent and 17 percent of schools in Massachusetts and Missouri, states that do not permit personal belief exemptions, permitted personal belief exemptions regardless.
- Between 1991 and 2004, the average state level of nonmedical vaccination exemptions rose from 0.98 percent to 1.48 percent.
- States that allow philosophical exemptions or make the application process for exemptions easy have higher rates of nonmedical exemptions. Between 2005 and 2011, the rates of nonmedical exemptions in states that permitted philosophical exemptions were 2.5 times higher than in states that only allowed religious exemptions.
- In 2008, the Centers for Disease Control and Prevention reported 131 cases of measles in the U.S., twice as many as the yearly average from 2000-2007. The CDC said the highest number of cases was reported among children who had nonmedical vaccine exemptions.
- Children who have not been vaccinated are 35 times more likely to contract measles than vaccinated children, citing a report in the Journal of the American Medical Association.
- Another JAMA study cited in the report stated that an increase in the incidence of pertussis in 2012 was 90 percent higher in states with both personal belief and religious exemptions than in states without personal belief exemptions.