Yes, vaccines are safe. We debunk the vaccine myths


August 5, 2015

Is autism linked to vaccines? Can I get vaccinated if I’m pregnant? How much is too much at one time? Experts answer these questions and more.

To better understand the importance of vaccinations and to dispel some common vaccine myths, hear from Dr. Kathryn Edwards, director of the Vaccine Research Program at Vanderbilt University Medical Center, and Dr. Sarah Elizabeth Williams, a clinical instructor in pediatrics at the Vanderbilt University School of Medicine.

How do we know vaccinations are safe?

Dr. Edwards: Vaccines are generally tested first in healthy adults so that we can make sure that the vaccines work in terms of making immune responses and also that they are safe. After they are found to be safe in normal, healthy people, studies are done with babies or older people, depending on the target population.

How are vaccines monitored?

Dr. Edwards: Vaccines are studied in efficacy studies to see whether they will prevent disease. During that whole time, we also look at safety. So, we see: Are there sore arms? Are there fevers? Once vaccines are recommended and licensed, there also are ways to look at vaccine safety by reporting events that happened after that. We have a large grant to look at vaccine safety — if there are reactions after vaccine, then we study them.

If there were a problem with the vaccine, how would the public be notified?

Dr. Williams: If there were some sort of problem with the vaccine or if there were any kind of contamination that we identified, that would be shared with the public and the authorities, or public health agencies would let people know.

Is there a link between vaccines and autism?

Dr. Williams: This idea that vaccines were somehow connected with the onset of autism in children first came about with one paper that was published by a group of investigators in England. The lead author was Dr. Andrew Wakefield, and the paper included eight children. Since that time, it has been found that the paper and the study included false data — he basically made up data and this is how a vaccine myth is born. All of the authors on the paper basically asked to be removed from the paper, the doctor lost his medical license in England, and the paper was retracted from the journal. Because of that article, everyone got very worried. There have been millions of dollars spent on studies trying to disapprove what he suggested. Over two dozen studies have all had the same finding: There is no link between vaccines that infants receive and autism.

Are there vaccines that aren’t safe during pregnancy?

Dr. Edwards: When you are vaccinating the mother, you are vaccinating the mother and the baby. There are a few vaccines that are live, weakened vaccines. The measles vaccines, the mumps vaccine, the rubella vaccine are all live vaccines, and we do not generally give those to pregnant women. The risk for influenza as a disease, particularly in the third trimester, is very high for hospitalizations and even mortalities. So, the flu vaccine, not the nose drop one, not the live one, but the shot is recommended for pregnant woman. The tetanus, diphtheria and pertussis (Tdap) vaccine is recommended for pregnant woman. That is not a live vaccine.

Can you receive too many vaccines at one time?

Dr. Williams: This is another vaccine myth. The babies are actually receiving less than what I received as an infant because we have refined what is in the vaccines. They are receiving less proteins or what we call antigens. So, the number of antigens that babies are exposed to in the first year of life is actually very small. Really, there is no concern about giving too many vaccines at one time.

Talk to your pediatrician about your family’s immunizations, or if your family needs a pediatrician, consider a member of the team at Monroe Carell Jr. Children’s Hospital at Vanderbilt.