One of my favorite topics! As many of you know, I'm passionate about vaccines, and passionate about providing factual information to my patients. There is so much false information out there, and it can be challenging as a parent to know what to believe. With that in mind, I break down the most commonly-discussed myths that I hear from my patients regarding their concerns about vaccines. -Dr. Lane
MYTH #1: VACCINES CONTAIN TOXINS SUCH AS ALUMINUM, MERCURY, AND FORMALDEHYDE
Aluminum is found naturally in large quantities in the air, soil, and water, and is consumed through drinking water or ingesting certain foods or medications. The average adult consumes 7-9 milligrams (mg) of aluminum every day. The maximum total amount of aluminum an infant could be exposed to over the first six months of life, based on the recommended vaccine schedule, is 4.2 mg. Over those first six months, infants receive more aluminum from their diet - approximately 7 mg if breastfeeding or 38 mg if drinking formula. Most aluminum we ingest is quickly excreted in stool, and much of what does remain and enter the bloodstream is then excreted in the urine.
Aluminum salts are used in vaccines as adjuvants - this means they help stimulant an adequate immune response (which may not happen from the killed or weakened virus or bacteria alone). The first vaccines were whole-cell vaccines, which meant they were highly immunogenic (i.e. induced good immunity), but were also likely to cause significant local and systemic side effects like febrile seizures. The improved safety of our current vaccines means they are less immunogenic by themselves. Aluminum salts are extremely effective at enhancing the antibody response, are well-tolerated, and have the strongest safety record of any adjuvant. Aluminum adjuvants can cause injection site pain and tenderness, and occasionally can lead to a persistent lump or granuloma at the injection site. Due to aluminum’s ability to induce the immune system, some people develop short-lived post-immunization headache, joint pain, or muscle aches. However, aluminum salts rarely cause severe local reactions or systemic inflammatory problems.
There is no elemental mercury in any vaccine, nor has there ever been. Methylmercury is the mercury found in old thermometers or fish; this has never been in vaccines.This concern arose over thimerosal , which is 50% ethylmercury. Ethylmercury and methylmercury are entirely different compounds, despite their similar names - think of ethanol (drinking alcohol) versus methanol (antifreeze, which will kill you if you drink it!). Even so, thimerosal was removed from all childhood vaccines in 2001.
Lastly, formaldehyde is used as a preservative in the vials containing vaccines. It inactivates the virus or bacteria being vaccinated against, so that it doesn’t cause disease when injected, and prevents the growth of other bacteria or pathogens in the vial. Formaldehyde is also a normal part of the human metabolism! It is created in our cells and processed by our livers in much larger amounts than found in vaccines. In the last 30 seconds, your liver metabolized approximately 11mg of formaldehyde, over 10x what an infant receives from all vaccines total. The average 2-month-old baby has 1.1mg of naturally occurring formaldehyde circulating in their bloodstream; the most present in any vaccine is 0.2mg.
MYTH #2: VACCINES CAUSE AUTISM
Study after study - looking at millions of children around the globe, over the last 2 decades - has disproven this hypothesis. There is NO association between vaccines and autism, the MMR and autism, or thimersol and autism. Researchers have even studied children who have siblings with autism, and thus are genetically predisposed to a higher risk of autism themselves, and there is still no link to vaccines.
Where did this myth come from?
In 1998, Andrew Wakefield and others published a paper in the medical journal Lancet where he linked autism to the MMR vaccine. He later admitted that he falsified the data, and lost his license to practice medicine. Mr. Wakefield obtained blood samples by paying children at a birthday party, without oversight from an ethics committee. He was working on a patent for his own measles vaccine, and had extensive financial involvement with the lawyers pursuing the MMR vaccine manufacturer in court. He lost all appeals to regain his medical license.
Since then, many anti-vaccine organizations have performed studies in an attempt to reproduce results linking the MMR vaccine or other vaccines to autism, and have not been able to find any connection.
What does cause autism?
There is no single cause. Research suggests that autism develops from a combination of genetic and environmental influences that affect crucial aspects of early brain development. Some affect how brain nerve cells, or neurons, communicate with each other, and others affect how entire regions of the brain communicate with each other. One current hypothesis being studied is an abnormality in myelin, the substance that insulates these nerve cells in the brain and therefore keeps messages moving smoothly.
Research shows that autism tends to run in families. Genetic risk factors include mutations in certain genes, such as those causing fragile X syndrome and other genetic disorders, as well as the presence of some metabolic disorders.
Environmental factors may further increase - or decrease - autism risk in people who are genetically predisposed. Importantly, the increase or decrease in risk appears to be small for any one of these risk factors, including being born to older parents, being born extremely premature, exposure to heavy metals and environmental toxins, and fetal exposure to certain medications. Most people who are exposed to these environmental risk factors will not develop autism.
MYTH #3: VACCINES CONTAIN CELLS FROM ABORTED FETUSES
Vaccines are typically grown in what’s called a cell culture - cells that are removed from their natural source (such as an animal or plant) and grown in a petri dish. A cell strain is a type of cell culture containing only one type of cells, such as skin cells or muscle cells.
Most vaccines have been developed using animal cell strains, like monkey kidney cells or chicken embryo cells. However, some pathogens, like rubella, don’t grow well in animal cells. Additionally, there is the threat of contamination from a virus or bacteria that was previously unknown to humans.
In the 1960s, the US was facing a rubella epidemic. Rubella causes congenital rubella syndrome if a mom is infected during her pregnancy, which can result in cataracts, deafness, heart disease, developmental delays, and microcephaly, as well as other conditions. Some women who because infected during pregnancy opted to terminate their pregnancies, and even to donate these fetuses to rubella research. A researcher was able to isolate the rubella virus from these fetal cells. At the same time, another researcher was able to develop a cell strain using lung cells from an aborted fetus. Many viruses, including rubella, grew well in this cell strain. The cell strain was proven to be free of contaminants and safe for human use.
It is important to note that fetal cells do not remain as actual ingredients of the vaccines. As part of the vaccine manufacturing process, they are purified so any fetal DNA or cell components are removed. Current vaccines are developed in the so-called "descendant cells" (many replications in a petri dish later) of the original fetal cell line from 40+ years ago.
Currently used-vaccines that were developed from cell strains started with human fetal cells include rubella (in the MMR vaccine), chickenpox, and hepatitis A.
MYTH #4: "TOO MUCH, TOO SOON"
In the first 18 months of your child's life, there are 25 recommended vaccines. Many parents are concerned about this increased number compared to their own childhood vaccines. However, today's vaccines are much more refined, so children are actually exposed to fewer antigens (the part of a virus or bacteria that your immune system responds to) and fewer preservatives!
The American Academy of Pediatrics' vaccine schedule is designed to build your baby's immunity at an early age. Of all age groups, young infants are the most likely to become severely ill or even die from vaccine-preventable illnesses, so it's important to vaccinate them as soon as possible. The recommended timing for each dose of a vaccine is based on 1) the age when the body's immune system can respond appropriately to provide optimal protection, and 2) the need to provide protection at the earliest possible time based on the highest-risk age for that disease.
There are various alternative schedules that have been proposed for vaccines - none of them have been shown to decrease side effects or adverse reactions. In fact, spacing out single vaccines instead of using combination vaccines actually INCREASES the risk of side effects and adverse reactions - combination vaccines contain less of each antigen, and less preservatives, than required for individual vaccines.
Babies are constantly exposed to antigens from viruses and bacteria - starting with the labor and delivery process. Even breastfeeding exposes infants to hundreds of antigens, much less laying on a blanket, crawling on the floor, or putting a teething toy in their mouth! The immune system of even a young infant is prepared to manage thousands of antigens every single day.
MYTH #5: UNVACCINATED CHILDREN ARE NOT A DANGER TO VACCINATED CHILDREN
Unfortunately, some children are unable to receive vaccines due to an immunodeficiency or illness, such as a child undergoing chemotherapy for cancer. Those children are particulary vulnerable to severe disease, and it's important that everyone around them be vaccinated to protect them (this is called "herd immunity").
Additionally, infants don't receive their first dose of certain vaccines until 12 months old, and may not complete all doses of vaccines series until age 4 - until then, they are still vulnerable to vaccine-preventable disease.
MYTH #6: THE DISEASES PREVENTED BY VACCINES AREN'T A BIG DEAL
Going back a few generations, approximately 1 in 5 children (20%!) died before their 5th birthday - this figure is unimaginable now! Many of these deaths were due to diseases that vaccines now prevent, such as diphtheria, measles, pertussis, and pneumococcal disease. Certainly improved socioeconomic conditions such as improved nutrition and better hygiene, and the development of antibiotics and other treatments, have played a role - but the biggest, most persistent drop in each of these diseases was seen directly after the licensure and widespread use of it's vaccine.
For example, before vaccines, nearly everyone in the US got measles, and as many as 6000 died from it each year, the majority children younger than 5 years old (not to mention the people with life-long side effects including brain damage from encephalitis). Measles was declared eliminated from the US in 2000, only to start making a comeback in recent years in areas with high percentages of unvaccinated children. Another example of vaccine success is diphtheria - before vaccines, it was a leading cause of childhood deaths, causing 15,000 deaths in the US per year. It is now virtually unheard of in the US, with only 2 total cases in the last 15 years.