Are vaccines safe? Do vaccines cause autism? And are vaccines really necessary? We went to the experts to dispel nine common myths about vaccines and get to the truth of the matter.
Fact: “When your baby leaves the womb, he’s bombarded with trillions of bacteria,” says Paul Offit, M.D., a pediatrician specializing in infectious diseases who co-invented the rotavirus vaccine. Each one can contain up to 6,000 “immunological components” that challenge the immune system. Vaccines contain no more than 160. If your child scrapes his knee, it’s more of a challenge to his immune system than all vaccines combined.
Fact: Despite the long tail of one discredited study, research on thousands of kids has proven beyond a doubt that vaccines do not cause autism. The latest report, which was published in the Annals of Internal Medicine in March 2019, examined 657,461 children born in Denmark between 1999 and 2010, and it found no link between the MMR vaccine and autism. Experts believe autism is caused by a combination of genetic and environmental factors.
Fact: Vaccines used to contain thimerosal, a mercury-containing preservative, but it’s a different compound than mercury. More important, it hasn't been used in childhood vaccines since 2001, when the FDA opted to remove it even though studies show it's safe. This form of mercury was never proven to be dangerous, and the multi-dose flu vaccine is the only vaccine that still contains it. Thimerosal's purpose was to keep bacteria from growing in multidose vaccine solutions. Vaccines that were once preserved with thimerosal are now put into single-dose vials or syringes that aren't susceptible to bacterial contamination.
Fact: The immunization schedule was tested and found to be safe. By following it, a child will be protected at the earliest age possible, says Julie Boom, M.D., Director of the Texas Children's Hospital Immunization Project. “Spacing out shots leaves babies at risk for infection.”
Fact: The U.S. Food and Drug Administration (FDA) puts every vaccine through stringent testing before making it available to the public. Afterwards, the organization, along with the Centers for Disease Control and Prevention (CDC), continues to monitor for vaccine-related problems. "If a child experiences a side effect from a vaccine, it's usually mild, such as fever – in 5 to 15 percent of vaccine recipients – or soreness or swelling at the injection site. More severe side effects, though rare, can also occur but at a rate far lower than the rate of severe complications from measles itself," says Matthew Kronman, M.D., assistant professor of pediatric infectious diseases at Seattle Children's Hospital.
Fact: Sure, your child's chances of catching a preventable disease are greatly reduced when other people are vaccinated. But 90 percent of the community needs to be vaccinated in order for herd, or community, immunity to be effective. Although the national vaccination rate hits this mark, disease outbreaks, such as the recent measles occurrence, tend to befall communities where childhood vaccination rates are much lower.
Fact: Your baby is tougher than he looks. "The small number of compounds from microorganisms contained in vaccines is nothing compared to the number produced by the thousands of germs a baby's immune system responds to every day," says Richard Rupp, M.D., director of the office of vaccine clinical trials at the Sealy Center for Vaccine Development at the University of Texas Medical Branch in Galveston. In fact, a baby's tiny body has the ability to make antibodies for up to 100,000 vaccines at once. But babies get about 26 vaccinations throughout their first two years, and they gain protection against only 14 different deadly diseases.
Fact: Deviating from the vaccination recommendations set by the CDC leaves your baby vulnerable to serious life-threatening ailments at a time when her immune system is still weak. "It takes time for a baby's immature immune system to build up enough antibodies to fight off disease," says Dr. Kronman. The CDC designed the vaccination schedule to offer infants the fullest disease protection as early as possible. Spacing out vaccines beyond these recommendations leaves a child open to preventable infection from bacteria and viruses. "Even though your baby gets some protection with the first dose of a vaccine, she isn't fully protected until the series of shots is complete," says Dr. Kronman.
Fact: The varicella (chickenpox) virus does more than just cause an itchy, unsightly rash. It puts a child at risk for serious health complications. Approximately one out of every 1,000 children who gets chicken pox develops severe pneumonia or a brain infection. Some develop group A streptococcus, a sometimes fatal disease more commonly known as flesh-eating bacteria. Before the varicella vaccine became available in 1995, up to two children died from the virus every week.