The side effects of vaccination definitely weigh on parents' minds.139,140 It may be reassuring to know that vaccines are constantly studied and monitored to make sure they are safe. Safety monitoring and testing continue long after vaccines are licensed.57
Although no medical intervention is 100% safe, the risk of serious side effects from vaccines, such as severe allergic reactions, is low.34
Any vaccination can result in an adverse reaction, but a serious reaction is extremely rare.141 For example, the risk a child will have a severe allergic reaction after the MMR (measles, mumps, and rubella) or DTaP (diphtheria, tetanus, and acellular pertussis) vaccine is less than 1 in 1,000,000.34
Even if a child were to have a life-threatening allergic reaction after being vaccinated, it could be brought under control by the staff at a doctor's office.9 While this possibility is definitely scary, it should be weighed with the benefits of helping to protect your child from dangerous vaccine-preventable diseases.
When you think about it, everyday life is full of risks. Consider driving, for example. Many of us drive with our children in the car, despite the risk of being on the road. As parents, we do our best to manage the risk by buckling our children in the safest car safety seats we can find.
Similarly, vaccines allow us to manage the risk of getting an infectious disease. If you consider that a child is far more likely to be seriously injured by an infectious disease than by any vaccine, the benefits of getting your child vaccinated outweigh the dangers. Why vaccinate?
Recently, there has been some concern about autism and vaccines.139,142 The increase in reported autism spectrum disorders (ASDs) made some parents wonder if there is a connection with vaccines.139,142,143 Yet, there hasn't been any scientific proof. More than 20 published scientific studies conducted in various countries have found no link between vaccination, specifically MMR vaccination, and ASDs.36 Moreover, a 2014 meta-analysis of more than 1.2 million children found that neither vaccines, nor vaccines components, are associated with the development of autism.161
Yet some parents still have questions about a possible link. One reason for this is timing: some parents of children with autism say they first noticed signs of it during the time their children received their 12- to 24-month vaccinations.37 Their children may have appeared normal before 1 or 2 years of age, and then they lost the language or social skills they had.35
Only carefully controlled studies can prove if vaccines cause autism and so far, they have not.36 A combined review of several studies analyzed the vaccination and medical records of children with and without an ASD. This study found no association between childhood exposure to vaccines and the risk of developing an ASD.161
A small, uncontrolled study of 12 autistic children in 1998 initially raised the question about a connection between the MMR vaccine and ASDs. Yet in 2004, 10 of the study's original 13 authors retracted the study's conclusions—and stated the data did not establish a link.37 What's more, the scientific journal that had published the original findings retracted the article after an investigation found the results to be false.38
According to the Minnesota Department of Health, the publicity resulting from this flawed study actually had some serious consequences. Some members of a local community heard about the alleged link between autism and vaccines and became concerned. Their children weren't vaccinated as a result. One of those children went to Africa and was diagnosed with measles after returning home to Minnesota.39 Because of this, the state had an outbreak on its hands. Twenty-three measles cases (more than 20 of which were considered related) were reported, with a total of 14 hospitalizations.13
A series of studies has shown the concern about a potential link between thimerosal and autism to be unfounded.40
Thimerosal, a mercury-containing vaccine preservative, has worried many parents because of an alleged link to autism.143 However, a series of recent scientific studies found no link between thimerosal and autism.40
Thimerosal was used in small amounts for more than 50 years in multidose vials of vaccines (which hold more than 1 dose) to prevent them from being contaminated by bacteria. As a precaution, thimerosal has been removed from or reduced to trace amounts in vaccines for children 6 years of age and younger, with the exception of multidose vials of inactivated influenza vaccines. For infants and children, a single-dose, no-preservative version of the inactivated influenza vaccine is also available.8
Even though thimerosal was removed from many vaccines almost 10 years ago, children continue to be diagnosed with ASDs.42,43 For many people, this is the most convincing evidence that thimerosal is not linked to autism.
Experts say there are indeed more people being diagnosed with ASDs. The increase in diagnoses is due in part to ASDs being more broadly defined and better recognized and diagnosed.35 The exact cause of autism is still being studied. Most scientists have agreed that genetics play a role.35
Toxicity is to be taken very seriously, especially when your child's safety is at risk. The truth is, some vaccine ingredients could be toxic, but at much higher levels than what is found in vaccines. Any substance—even water—can be toxic given a large enough dose.9
We might not be aware of it, but we are exposed to small amounts of these same substances everyday. For example, the average person takes in an estimated 30mg to 50mg of aluminum everyday, mainly from foods, drinking water, and medicines. Not all vaccines contain aluminum, but those that do typically contain just trace amounts: about 0.125mg to 0.625mg per dose, or roughly 1% of that daily average.9
Of course the pros and cons of vaccination should be given careful thought. But if you consider that a child is far more likely to be seriously injured by an infectious disease than by a vaccine, the benefits of getting your child vaccinated far outweigh the risks.57
By choosing not to vaccinate a child, some parents may be hoping that their child won't be exposed to the disease. But it's important to remember that we live in a global society. This country may not have seen polio in more than 10 years, but people fly in and out of the United States everyday. Just 1 infected traveler could set us back more than 50 years if our own population isn't protected. This is why it's so important to keep vaccinating our children.9
You're not just helping to protect your own children by getting them vaccinated. You're helping to protect other children and adults in your community, too. This could be your school community, your playgroup community, your neighborhood, even your faith community.
For example, your community may have children who can't receive certain vaccines for medical reasons or because they're too young to be vaccinated. If these children are exposed to someone with an infectious disease, they can catch the disease. By getting immunized, your community could help protect these children from vaccine-preventable diseases by reducing the chance of these diseases spreading from person to person.
Let's consider a community where most people are immunized. Even if 1 child gets sick, the infection will likely not spread because it has nowhere to go. This phenomenon is called herd immunity.144 But if fewer people in a community are immune, it is easier for a disease to spread and lead to an outbreak. In fact, outbreaks of measles, mumps, and pertussis are occurring around the United States.12,57,155