TUESDAY, May 12, 2015 (HealthDay News) -- A small minority of people still distrust the safety of routine childhood vaccinations, but one expert says the myths that swirl around vaccines are easily dismissed.
"Both parents and doctors have the same goal, to keep a child healthy, and the best way to keep a child safe is through vaccination," said Dr. Nadia Qureshi, a pediatric infectious disease specialist at Loyola University Health System in Chicago.
According to the U.S. Centers for Disease Control and Prevention, vaccines have saved more than 732,000 lives in the United States over the past two decades.
But misconceptions about these simple but crucial health care interventions persist.
One major myth is that the measles-mumps-rubella (MMR) vaccine causes autism, said Qureshi, who is also an assistant professor of pediatrics at Loyola University.
"This myth began in 1998 when an English surgeon published a study in The Lancet journal claiming the MMR vaccine was associated with autism and inflammatory bowel disease," she said in a Loyola news release.
However, since then, "no other studies have been able to replicate or validate these results," Qureshi noted.
In fact, "later, it was discovered that [the British surgeon] had fabricated and plagiarized clinical records, and even was found to have patented a single vaccine for measles so the research finding would benefit him financially," she said.
"Also, to prove his theories the author performed procedures on children that were not necessary nor approved by the hospital's ethics committee," Qureshi said. "His medical license was revoked and paper was retracted. Still, the unfounded fear has been instilled in many parents' minds and continues to result in vaccine hesitancy resulting in widespread outbreaks."
Just last December, a measles outbreak that began at two Disney Parks in California infected 151 people before it was declared over in April, according to the CDC. More than 80 percent of those who were infected were unvaccinated or did not have proof of vaccination, CDC officials have said.
Another myth about vaccines: "Too many vaccines at one time is dangerous."
"The immune system is constantly being challenged from what infants place in their mouths to even the air they breathe, every day they are exposed to thousands of germs and antigens," Qureshi pointed out. In that context, "Vaccines are like a drop of water in a swimming pool," she said.
Furthermore, "extensive research has been done to ensure the vaccine schedule is safe and effective," Qureshi added. "If parents wait too long to give the vaccines, they miss the window when children are most vulnerable and more likely to have complications if they are infected with a virus. This is especially true for pertussis or whooping cough when infants have a higher death rate."
Some people also have the mistaken belief that vaccines contain toxic substances.
"The three ingredients that most commonly concern parents are thimerosal, aluminum and formaldehyde," Qureshi said.
However, "since 2000, thimerosal has been removed from almost all vaccines in response to popular fears [that remain scientifically unproven]," she said. "Aluminum is used to help create a better immune response and the amount in a vaccine is 1/100th of our daily consumption. Formaldehyde is naturally found in plants, animals and humans. The level of formaldehyde found naturally in the body is greater than 100 times that which is found in a vaccine."
To put it in context, "a pear has 50 times more formaldehyde than a vaccine," she said.
Finally, some people may believe that it's better their children develop immunity through infection and possibly sickness -- instead of from a vaccine.
However, "in some cases the opposite is true," Qureshi said.
"For instance, vaccines for HPV, Hib and tetanus provide better immunity than if a person gets the infection," she said. "Thanks to vaccines, we often forget that many of these diseases can cause lasting complications, even death. Hib meningitis can lead to mental retardation, polio can cause paralysis and measles can kill."
And while, "the risk of having a serious adverse reaction to a vaccine is 1 in a million, the risk of complications from a vaccine-preventable infection is closer to 1 in 100 to 1 in 1000," Qureshi said.
The U.S. Centers for Disease Control and Prevention has more about vaccines.