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Vaccines: What's Right for Your Baby?

To vaccinate or not to vaccinate -- that was the dilemma Katie McBride* faced when her daughter Jenna was born. On the one hand, she knew moms who questioned the safety of childhood vaccines; on the other, she knew scientists who trusted the testing behind them. "Obviously I didn't want my child to die from some horrible disease," says the Evanston, Illinois, mom, "but I was uncomfortable not knowing the risks and benefits of the vaccinations either." McBride ultimately chose to have Jenna vaccinated but opted to stagger a few of the shots.

Today's children are immunized by age 13 against some 16 diseases (or 53 vaccine doses), including measles, mumps, rubella, diphtheria, tetanus (lockjaw), pertussis (whooping cough), hepatitis A and B, meningitis, pneumonia, polio, chicken pox, flu, rotavirus and the human papillomavirus (HPV). Whew! That's more vaccines than ever -- 30 years ago, children received only seven -- but it doesn't necessarily mean babies have more injected into them than they used to. "Immunizations today are more purified than those of the past," says pediatrician Ari Brown, M.D., a spokesperson for the American Academy of Pediatrics (AAP) and co-author of Baby 411. For example, the DPT shot (diphtheria/pertussis/tetanus) that children received in 1980 was made from a blend of more than 1,000 bacteria, or antigens (substances that prompt the body to make disease-fighting antibodies). Today's vaccine, DTaP, delivers only three to five antigens. And whereas the polio vaccine at one time had a live virus that would trigger a minute case of polio for the body to fend off, the newer shot has no live virus. "It's a win-win for babies because they receive protection from more diseases from a smaller number of antigens," Brown says.

This year alone, the shots will prevent some 14 million cases of illness and 34,000 deaths from disease, according to research estimates by Fangjun Zhou, Ph.D., a health scientist in the Immunization Services Division at the Centers for Disease Control and Prevention (CDC). To ensure safety, all vaccine-manufacturing facilities and products are licensed by the Food and Drug Administration (FDA), and every vaccine lot is tested by the manufacturer. The FDA then reviews those results and requires a sample of its own to test.

Yet some parents still choose not to vaccinate. They have doubts about the safety of the vaccines, or they believe the threat of the diseases has passed. But recent outbreaks of measles and whooping cough, which were ultimately traced to unvaccinated children who traveled to other countries, suggest that immunization may be as critical as ever. "There are lots of myths about vaccines, but the reality is that they are one of the most important things you can do to protect your kids against serious, sometimes life-threatening, infections," says Brown. "As a mom and a pediatrician, I vaccinate my own kids for that reason."Pediatricians immunize children as part of routine care using guidelines devised by the AAP, the American Academy of Family Physicians (AAFP), and the CDC. Here's what you need to know to help you make informed decisions about vaccinating your child.

Question: Can vaccines cause autism?

The concern stems chiefly from the preservative thimerosal, a compound containing mercury. It was used in many vaccines until it was phased out in 2001 as part of an FDA-led campaign to reduce mercury exposure in children. Some people believe thimerosal is a neurotoxin, a substance that damages nerve tissue, and that it harms developing brains.

Cornelia Read of Exeter, New Hampshire, blames the ingredient for her daughter's autism. "Lila was perfectly fine -- talking, making eye contact and very social -- until she was 13 months old," says Read. "Now, at age 15, she is nonverbal and cognitively about the level of a 1-year-old." Read became suspicious of thimerosal after reading an article depicting autism as a form of mercury poisoning.

Though thimerosal has been ousted from most vaccines (it's still used in some versions of the flu shot), some parents continue to blame the rise in autism and other developmental disorders on environmental toxins they claim the shots contain.

Facts: "There are a large number of well-designed studies involving thousands of children over the past decade that show no connection between vaccines and neurodevelopmental problems such as autism and ADHD," says Jeanne Santoli, M.D., deputy director at the CDC's National Immunization Program. Even after thimerosal was removed from most vaccines, autism rates have continued to climb. "You'd expect that if a link was there, we'd have seen a decrease after thimerosal was removed," Santoli says. "But we've seen no such drop-off." It's important to note that methylmercury, which contaminates fish and pollutes lakes, can build up in the body and lead to nerve damage; but thimerosal contains ethylmercury, a different type of mercury that is much less likely than methylmercury to accumulate in the body and has not been shown to have adverse effects.

Earlier this year, the U.S. Court of Federal Claims ruled that vaccines do not cause autism, rejecting the high-profile cases of three unrelated plaintiffs. The rulings found no evidence that the MMR shot, which immunizes children against measles, mumps and rubella, had caused the children's disorders.

Question: Do vaccines contain toxic ingredients?

Along with weakened or killed viruses or bacteria, vaccines also contain preservatives and agents called adjuvants that stimulate an immune response. Some parents worry about the adjuvant aluminum, which is found in several new vaccines. Pediatrician Robert Sears, M.D., a co-author of the Sears Parenting Library and author of The Vaccine Book: Making the Right Decision for Your Child, is concerned about the lack of scientific evidence to confirm that aluminum is safe for infants when injected. He notes that doctors delay those vaccines containing aluminum for premature babies in neonatal intensive care units until they reach a certain weight because it may damage brains and nervous systems that are not fully developed. For those reasons, Sears recommends his patients limit the aluminum-containing vaccines to one per month.

The amount of aluminum and other ingredients being given to babies in vaccines has scared away some parents entirely. "Something is causing so many children to be diagnosed with attention deficit and hyperactivity disorder, autism, allergies, and other diseases and disorders," says Samantha Remeny of Brentwood, California, who has opted not to immunize her 13-month-old son. "I believe that the vaccines that contain neurotoxins like aluminum, and the massive vaccination schedule recommended by the CDC, are at the root of the problem." Remeny once worked in sales at a pharmaceutical company and knows how important it is to read the package inserts and understand the risk of adverse reactions. "When you read the ingredients of these vaccines, it's scary to see that they routinely use substances -- aluminum, ammonia and formaldehyde -- that can cause neurological damage," she says. "There was a big deal a couple of years back about aluminum in deodorants and a possible link to Alzheimer's disease, so if a topical preparation containing aluminum [raised red flags], why would an injection be any safer?"

Facts: "If you dig a little deeper, you'll find that all of the ingredients in vaccines have been studied and found to be safe and nontoxic," says Brown of the AAP. Aluminum, for example, is not like the foil you use in the kitchen but is a type of salt whose role is to provoke the body into mounting an immune response. Not only do we get aluminum from our environment -- in air, water, soil, formula, even breast milk -- but research on animals shows that after aluminum is injected, the body effectively and rapidly eliminates it. "Although aluminum salts in a vaccine do circulate through the bloodstream, most of it binds to a protein called transferrin that then carries it out to the kidneys, where it gets eliminated in urine," Brown explains. "Fifty percent of the aluminum in vaccines -- as well as from food -- comes out in your pee in less than 24 hours." (Some 85 percent is gone in two weeks, and 96 percent is gone within three years.)

The formaldehyde in vaccines is not the same stinky stuff from your high-school anatomy class. This type actually occurs naturally in the body as a byproduct of metabolism, and there's more already in your system than in any vaccine. "These ingredients are not put in there willy-nilly," Brown says. "They're probably more studied than Tylenol."

Rebecca Leibowitz of Scotch Plains, New Jersey, works in research and development for a medical device company and is aware of the rigor that pharmaceuticals -- including vaccinations -- go through to earn FDA approval. "I know that substantial proof of safety is required," says the mother of two boys, 6 and 4. "And just as I look to a professional plumber to recommend the best water heater for my house, I also look to a professional pediatrician to recommend what's best for my children."

Question: Can vaccines cause dangerous side effects?

Isabelle Wilder* of Delray Beach, Florida, stopped vaccinating her four children after the third was 15 months old. "My belief is that vaccines interact negatively with the chemical or biological makeup of some individuals, and there's no way to predict who will be affected," she says. Wilder herself has an autoimmune disease and once broke out in a rash from handling a prewrapped croissant from a foreign country. Her children have shown sensitivities to all kinds of substances from milk to cosmetics to penicillin to oak pollen. "Our family presents a pattern of immune system reactions, possibly triggered by vaccines," she says. Wilder's eldest child has an auditory processing disorder (his brain has trouble processing sounds and spoken language); her second child has ADHD; and her third child was diagnosed with autism. Her youngest, who was never vaccinated, seems fine.

Facts: The Vaccine Adverse Event Reporting System, a CDC and FDA safety surveillance program, has been tracking vaccine side effects since 1990. According to the FDA, most side effects are mild and temporary, including a sore arm, mild fever, headache and fatigue. (A fever is a sign that your body is fighting off something.) According to the CDC website, 1 in 20 patients will develop a mild rash after the MMR vaccine, and 1 in 25 might develop a mild rash after the varicella (chicken pox) vaccine. Although side effects vary by shot, around 1 in 16,000 patients will develop a fever of 105 degrees Fahrenheit or higher, and around 1 in 14,000 will have seizures after the DTaP vaccine. Fewer than 1 in 500,000 children will have a severe allergic reaction involving major swelling, difficulty breathing and a significant change in behavior -- acting very sluggish, seemingly out of it. (As with any significant change in behavior or appearance, call 911 if you notice this in your child,) According to the CDC, "so few deaths can plausibly be attributed to vaccines that it is hard to assess the risk statistically."

Question: Can too many vaccines overload a young immune system?

Some 40 percent of parents recently surveyed said they worry about too many vaccines given in a single doctor's visit, according to CDC findings presented earlier this year at the National Immunization Conference in Dallas. Judy Van de Water, Ph.D., is an immunologist at the University of California, Davis, who is directing an investigation, funded by the National Institutes of Health (NIH), into the potential environmental risk factors that may be behind the rise in autism. "A healthy child should do fine with our current vaccination schedule," she says, "but you can't always know how robust a child's immune system will be prior to vaccination."

Some experts suggest that some children who develop autism have faulty immune systems. A 2008 study published in the journal Autism Research compared levels of immunoglobulin (antibodies that play a role in immunity) in normally developing children with the levels in children with autism. It showed that children with autism had lower levels of immunoglobulin, suggesting "an underlying defect in immune function." A 2009 study published in the journal Brain, Behavior and Immunity did a similar comparison and found abnormalities in the "natural killer cells" (the big guns of the immune system) of children with autism spectrum disorders, which "may predispose them to the development of autoimmunity and/or adverse neuroimmune interactions during critical periods of development."

"Since some vaccines are designed to mimic infections," Van de Water says, "you can imagine how sick you could be if you get nine at once and your immune system is not working optimally -- for any number of reasons." She and her team are developing a heel-stick test that will determine the health of a child's immune system before immunization, but it's still years away from FDA approval. In the meantime, if your child has a bad response to an early vaccine -- acting very lethargic for more than 24 hours and running a fever of 100 degrees Fahrenheit or higher -- Van de Water suggests that it may sound a warning about future vaccinations. For other signs of how the state of a patient's immune system impacts immunization, visit the CDC website (

Facts: "Just by breathing air, eating food and sticking toys in their mouths, babies and kids encounter many more foreign substances every day than the ones in their vaccines," says Martin G. Myers, M.D., a pediatrics professor at the University of Texas Medical Branch at Galveston and author of Do Vaccines Cause That?! A Guide for Evaluating Vaccine Safety Concerns. "Consider that a baby's immune system is assaulted with billions of foreign substances within seconds of birth, whereas all the childhood vaccines put together have far less antigens."

As Brown notes, vaccines today are not only highly purified, packing a bigger punch using less vaccine material, but the material itself is safer. "With smallpox, the first successful vaccine ever developed, your body would mount an immune response to a tiny bit of a real germ to prepare the body for exposure to an actual infection," she explains. With advanced medical technology, most of today's vaccines rev up your immune system to make antibodies (like smart bombs with memory) for the germ's signature or calling card -- not the germ itself. This way, if your body does encounter the germ, it will recognize its calling card and launch the smart bombs to fight it off.

Question: Is it okay to skip or delay vaccines?

Bernadine Healy, M.D., former head of the NIH, has argued that parents can legitimately question the need to give a 1- or 2-day-old baby a vaccine against hepatitis B, a sexually transmitted disease, when babies have almost no risk for that disease. "That's a heavy-duty vaccine given on day two [of life]," Healy has said.

Robert Sears agrees that parents have the freedom to delay vaccinations for diseases that they feel don't pose a high risk to infants. He offers patients an alternative vaccination schedule that includes the most critical jabs -- for whooping cough, meningitis and rotavirus, for example -- and holds off on the others, including hepatitis A and B, chicken pox, polio and flu. "More and more parents are choosing not to vaccinate because they don't want to follow the overloaded schedule that the government mandates," he says. "I think more parents would vaccinate if doctors offered to spread the shots out in a manner that more babies can safely tolerate." Sears does believe the missed shots should be made up eventually, from age 2 to around 9, when immune systems are more developed.

Kellyx Nelson of San Francisco chooses to stagger shots for her son, Spyder, 15 months. "I space them out to help reduce discomfort," she explains, "and to isolate the variables if he does have a reaction." But she admits that it makes her nervous when the family travels around the country.

Facts: The timing of vaccines is designed to maximize children's immunity when they're most vulnerable to disease, according to the CDC. "Whooping cough is a lot worse in a 2-month old than in a 2-year old," Brown says. "By delaying vaccines, you're putting children at risk precisely when they need disease protection most."

Andrea Panico of Montclair, New Jersey, was initially disappointed that she wasn't able to split the MMR shot into its individual components for her daughter Thea, 17 months. "A week later there was a suspected case of measles in Thea's day-care," Panico recalls, "so I was pretty glad she'd gotten the vaccine for it."

If you have concerns about the timing of your child's vaccinations, discuss them with your pediatrician. What's more, not all vaccinations are mandatory in all states, and some allow for exemptions based on religious and philosophical views. (Go to to see vaccination requirements by state.)

Ultimately, the most important question you can ask pediatricians is how they handled vaccinations with their own kids. "We wouldn't do anything different for our own children than we do for our patients," Ari Brown says. "I vaccinated my kids, and I recommend vaccinations for my patients. My patients are my kids too."