This article has been reviewed by Thanai Pongdee, MD, FAAAAI, Website and Social Media Medical Editor
Vaccines are an effective means of preventing life-threatening illnesses by boosting the body’s natural immune response to diseases caused by viruses and bacteria. Vaccine programs throughout the world have led to improved overall health of our population by reducing the transmission of disease, permanent and temporary disability, and infant mortality. Although vaccines have been proven to be both safe and effective based on sound scientific evidence, several myths have been spread, keeping vaccines at the center of controversy. The top five vaccine myths are addressed here in an effort to emphasize the safety and necessity of this important healthcare intervention.
Myth 1: Vaccines contain many harmful ingredients.
Fact: Vaccines contain ingredients that allow the product to be safely administered. Any substance can be harmful in significantly high doses, even water. Vaccines contain ingredients at a dose that is even lower than the dose we are naturally exposed to in our environment. Thimerosal, a mercury-containing compound, is a widely-used preservative for vaccines that are manufactured in multi-dose vials. We are naturally exposed to mercury in milk, seafood, and contact lens solutions. There is no evidence to suggest that the amount of thimerosal used in vaccines poses a health risk. Many vaccines now produce single-dose vials which has greatly decreased the use of thimerosal in vaccines. Formaldehyde, another vaccine ingredient, is in automobile exhaust, household products and furnishings such as carpets, upholstery, cosmetics, paint and felt-tip markers, and in health products such as antihistamines, cough drops and mouthwash. The dose in vaccines is much lower than the amount we are exposed to in our daily life. Not all vaccines contain aluminum, but those that do typically contain about .125 mg to .625 mg per dose. This, too, is much less than what the average person consumes in a day. An estimated 30 to 50 mg of aluminum is consumed by the average person daily, mainly from foods, drinking water and medicines.
Myth 2: Vaccines cause autism and sudden infant death syndrome (SIDS).
Fact: Vaccines are very safe. Most vaccine reactions are usually temporary and minor, such as a fever or sore arm. It is rare to experience a very serious health event following a vaccination, but these events are carefully monitored and investigated. You are far more likely to be seriously injured by a vaccine-preventable disease than by a vaccine. For example, polio can cause paralysis, measles can cause encephalitis (inflammation of the brain) and blindness, and some vaccine-preventable diseases can even result in death. The benefits of vaccination greatly outweigh the risk, and without vaccines many more injuries and deaths would occur. Science has not yet determined the cause of autism and SIDS. These diagnoses are made, though, during the same age range that children are receiving their routine immunizations. The 1998 study that raised concerns about a possible link between measles-mumps-rubella (MMR) vaccine and autism was retracted by the journal that published it because it was significantly flawed by bad science. There is no evidence to link vaccines as the cause of autism or SIDS.
Myth 3: Vaccine-preventable diseases are just part of childhood. It is better to have the disease than become immune through vaccines.
Fact: Vaccine-preventable diseases have many serious complications that can be avoided through immunization. For example, more than 226,000 people are hospitalized from influenza complications including 20,000 children. About 36,000 people die from influenza each year. Vaccines stimulate the immune system to produce an immune response similar to natural infection, but they do not cause the disease or put the immunized person at risk of its potential complications.
Myth 4: I don’t need to vaccinate my child because all the other children around him are already immune.
Fact: Herd immunity occurs when a large population of a community is immunized against a contagious disease, reducing the chance of an outbreak. Infants, pregnant women and immunocompromised people who cannot receive vaccines depend on this type of protection. However, if enough people rely on herd immunity as the method of preventing infection from vaccine-preventable diseases, herd immunity will soon disappear.
Myth 5: A child can actually get the disease from a vaccine.
Fact: A vaccine causing complete disease would be extremely unlikely. Most vaccines are inactivated (killed) vaccines and it isn’t possible to contract the disease from the vaccine. A few vaccines contain live organisms, and when vaccinated lead to a mild case of the disease. Chickenpox vaccine, for example, can cause a child to develop a rash, but only with a few spots. This isn’t harmful, and can actually show that the vaccine is working. One exception was the live oral polio vaccine, which could very rarely mutate and actually cause a case of polio. However, oral polio vaccine is no longer administered in the United States.