Chief Science Correspondent
The recent measles outbreak at Disneyland earlier this week is just one example of a problem that is spreading across the nation.
A since-discredited (and unreplicable) 1998 study linking vaccines to autism has led to a widespread anti-vaccination sentiment across the United States, leaving hundreds of children susceptible to preventable diseases. The number of unvaccinated kindergartners has increased steadily since 2007, with current rates at 5.7 and 2.9 percent in private and public schools, respectively. Vaccination exemption laws are set by each state.
All 50 states allow for exemptions due to medical reasons. In 48 states (Mississippi and West Virginia excluded), parents can opt out of vaccines for religious reasons. In 17 states, parents can also opt out of vaccines for "philosophical" reasons.
In an article on thepeopleschemist.com, alternative medicine author and advocate Shane Ellison cites vaccination as a personal choice, claiming that vaccination laws intrude on his freedom as a parent. He attacks the concept of herd immunity, stating that doctors use "fuzzy logic" when supporting what Ellison dismisses as "only a hypothesis."
Ellison argues that his choice not to vaccinate his children does not harm others because if vaccinations actually work, the children of parents who believe in the vaccinations should not be harmed. But Ellison has missed the point of herd immunity entirely.
Herd immunity protects people (including infants and the elderly) who have weak immune systems and are unable to safely receive vaccinations. These individuals are at high risk of contracting otherwise preventable diseases but are protected by high immunity rates within the community. If the majority of a person's peers are vaccinated, they will most likely not come into contact with a person carrying the disease.
Ellison's children are benefiting from herd immunity. However, as the number of unvaccinated individuals increases, the effectiveness of herd immunity decreases. When parents choose to reject vaccinations, they are putting both their children and their children's peers at risk.
I focus on children because many of these viral infections are most prominent during childhood, and children tend to contract these types of diseases more frequently. But in reality, vaccination rejection has the poses a danger to the entire community. Many anti-vaccine advocates are quick to point out that vaccines are not 100 percent effective. This statement actually undermines their own argument; if vaccines sometimes fail, unvaccinated children (who will likely contract a variety of diseases) can pass these diseases onto their peers.
Additionally, the choice not to vaccinate decreases the likelihood of eventual eradication. Measles, for example, was previously very controlled within the U.S. population. In 2000, the Centers for Disease Control and Prevention declared that the disease has been eliminated from the U.S. Since then, the virus has entered the country via international travel. This is not a problem - as long as the vast majority of the population is immunized (The measles vaccine is documented to be approximately 98 percent effective, according to the CDC. But when more people refuse the vaccination, the chance of an outbreak increases greatly.
Many parents cite the potential side effects of vaccines as dangerous. Many advocates are quick to point to the most severe of these effects. One blogger, Cathy Jameson provided a list of every side effect she could find associated with vaccines including brain swelling, autism and death. Yet Jameson made a critical, but common mistake - she failed to cite any sources for these claims.
Parents want to protect their children, so this fear is understandable. But the truth is that exposing children to a slew of diseases is much more dangerous than an injection of an inactivated virus. Over 100 children died from the flu in the 2012-2013 season. 90 percent of those patients were unvaccinated.
Death is a side effect of negligence to vaccinate. We are fortunate enough to live in a nation where preventative vaccines are readily available so that children don't have to suffer from the diseases that were common in the past.