Vaccines have proven to be one of humankind’s greatest inventions and the single most powerful and effective way of reducing disease and improving global health. Here are five facts you should know about vaccines:
1. When a critical portion of a community is immunized against a contagious disease (typically between 85-95 percent), the remaining members are also protected because there is little opportunity for an outbreak. Even those who are not eligible for certain vaccines—such as infants, pregnant women, or immunocompromised individuals (e.g., children with leukemia)—get some protection because the spread of contagious disease is contained. This is known as "community immunity" or “herd immunity” and is the primary benefit of vaccines both to individuals and to society.
2. For each virus, statisticians are able to calculate the minimum percentage of community immunity necessary to achieve herd immunity and prevent an outbreak. Though we only need about 85 percent of the community to have immunity to rubella, smallpox, and diphtheria to prevent an outbreak, diseases such as whooping cough (pertussis) and measles require at least 94 percent immunity. This is why public health experts argue that exemptions to vaccinations should be limited to those who are unable to vaccinate because of health reasons. When parents refuse to vaccinate their children for philosophical reasons, they increase the risk of disease exposure for the entire community.
3. Annual use of recommended vaccines for children has been estimated to avert up to 3 million deaths per year globally, with even greater numbers of prevented cases of illness and substantial disability. For children born in the U.S. in 2009, routine childhood immunization will prevent an estimated 42,000 early deaths and 20 million cases of disease, with savings of $13.5 billion indirect costs and $68.8 billion in societal costs.
4. In 2011, the Institute of Medicine (IOM), the health arm of the National Academy of Sciences and an independent, nonprofit organization that works outside of government to provide unbiased and authoritative advice to decision makers and the public, performed an analysis of more than 1,000 research articles on vaccines. The analysis by a committee of experts concluded that few health problems are caused by or clearly associated with vaccines.
The review of possible adverse effects of vaccines found convincing evidence of 14 health outcomes—including seizures, inflammation of the brain, and fainting—that can be caused by certain vaccines, although these outcomes occur rarely. In addition, the evidence shows there are no links between immunization and some serious conditions that have raised concerns, including Type 1 diabetes and autism.
5. Despite nearly thirty years of research, there has been no causal connection established between vaccinations and autism. However, the claim that vaccines caused autism was given credence in 1998 by the publication of a fraudulent research paper in the British medical journal The Lancet.
That paper was later retracted when it was discovered that the chief researcher, a British surgeon named Andrew Wakefield, had manipulated the data and failed to disclose that he had been paid more than $600,000 by lawyers looking to win a lawsuit against vaccine manufacturers. Wakefield also was found to have committed numerous breaches in medical ethics, including using some of the children named in the lawsuit in his study. In May 2010, British regulators revoked Wakefield’s license, finding him guilty of “serious professional misconduct.” They concluded that his work was “irresponsible and dishonest” and that he had shown a "callous disregard" for the children in his study.
Despite being discredited for fraud and unethical conduct, Wakefield is still considered the primary source and champion for those who erroneously believe in the connection between autism and vaccines.
