On Vaccinations

A bunch of children in Iron Lungs with polio. Skip the vaccines and these could be your kids. (Image c/o The Atlantic)

Untied is honored to have Tina M. Cairns, PhD.  University of Pennsylvania Department of Microbiology, submit a guest post on the topic of vaccination. Please take a few minutes out of your day to read her incredibly detailed, researched and articulate perspective. 

No polio is great. Everything tastes better. The Internet’s helped. Been reading that a lot to catch up.”  ~Steve Rogers, commenting on 21st century America (Captain America: The Winter Soldier)

As I sat in the theater watching the epic comic book-to-screen goodness that is Captain America: The Winter Soldier, this one quote resonated with me.  Our primary weapon in the fight against infectious diseases is vaccination.  Vaccines have lead to the global eradication of smallpox and a polio-free United States.  Yet vaccines remain terribly misunderstood by many and vilified by some.  Vaccines have become a victim of their own success; many once-feared childhood diseases are gone and with them the memory of what they inflicted.  Now vaccines are the target of that fear, and the internet provides an ample breeding ground for those fears to spread.

One of the most common misconceptions of vaccination is that vaccines give you the disease that they are trying to prevent.  What vaccines actually do is provide your immune system with a blueprint of the enemy.  Your immune system has time to study this blueprint and when the real enemy (virus/bacteria) is actually encountered, your body is two steps ahead and can easily defeat it.  All of this is accomplished without your body undergoing the burden of fighting disease.  Let’s take the flu vaccine for example.1  I’m sure that you’ve heard someone say, “I got the flu from the flu shot!”  The flu shot utilizes killed virus, incapable of infecting cells and causing disease.  Common side effects from the flu shot include soreness at the site of injection and low-grade fever.  These symptoms do not constitute catching “the flu.”  However, there is another type of flu vaccination, a nasal mist, which does contain a live virus.  This virus has been attenuated (weakened) so that it does not function like the flu virus found in nature.  The attenuated flu virus is sensitive to heat and cannot live inside the toasty 98oF of a human body, and therefore cannot infect the body’s cells and cause disease.  If a person actually gets the flu after receiving the flu shot, it is because they were already infected prior to or soon after their vaccination.  It takes, on average, two weeks for your body to build protection from a vaccine.  All that being said, live virus vaccines are not recommended for immunocompromised individuals (such as those undergoing chemotherapy) because there is a small chance that they will not be able to handle even a weakened virus.  Other live (attenuated) virus vaccines are the MMR (measles-mumps-rubella), chickenpox, and rotavirus vaccines.

Another mistaken belief is that vaccines cause autism.  What is interesting about this misconception is the number of different ways vaccines have been blamed for autism.  Three of the most cited are:

1) The MMR vaccine causes autism. This fear was fueled by the release of a paper in the journal The Lancet in 1998.2  The lead author, Andrew Wakefield, found evidence of measles virus in the guts of several children, which correlated with their MMR vaccination and autism diagnosis.  However, many other studies flat-out refuted this claim.3  In 2010, a review board found serious errors in the Wakefield paper and it was subsequently retracted by The Lancet.4,5  Andrew Wakefield was found guilty of ethical misconduct and erased from the UK doctor’s register.6

2a)  The mercury preservative thimerosal causes autism.  Thimerosal was removed from all pediatric vaccines in 2001 in response to public concern about mercury (even though all evidence to date says thimerosal-containing vaccines are safe).  The only vaccines that presently contain thimerosal are multi-dose flu shots (these are usually what you get at the local pharmacy and are not given to children).  So, if mercury was causing autism, we should’ve seen a drop in autism upon its removal, right?  Unfortunately, thimerosal was not the smoking gun some thought it to be; autism diagnoses continue to rise, yet people erroneously still cite the non-existent mercury in vaccines as a cause.7

2b)  “Toxins” in vaccines cause autism.  Related to the mercury hypothesis, this more general claim points the finger at just about every other ingredient in vaccines (such as formaldehyde, aluminum, and even salt), and some ingredients that are not even in vaccines (ether and antifreeze)!  The CDC provides a complete list of vaccine ingredients on their website: http://www.cdc.gov/vaccines/vac-gen/additives.htm.  Remember, “the dose makes the poison.”  Even water is toxic at high levels.8  In vaccines, all ingredients are at non-toxic doses.

3) Too many vaccines are given too soon, leading to autism.  The thought behind this theory is that a child’s immune system is “overloaded” upon receiving multiple immunizations at once.  Author Dr. Bob Sears even champions a revised vaccine schedule, which spaces out the shots over longer periods of time.9  Dr. Sears’s revised schedule is not based on science, results in more trips to the pediatrician, and, worse yet, leaves children unprotected when they should have already been vaccinated.  A 2013 study in the Journal of Pediatrics found that “parental concerns that their children are receiving too many vaccines in the first 2 years of life or too many vaccines at a single doctor visit are not supported in terms of an increased risk of autism.”10

Hi, I’m Jenny McCarthy. You may remember me from my boobs. You should totally take medical advice from me.

The “vaccines cause autism” misconception is continuously perpetuated in the media by celebrities such as Jenny McCarthy, Donald Trump, and most recently Kristin Cavallari (wife of Chicago Bears’ quarterback Jay Cutler).  Just last week the restaurant chain Chili’s cancelled an autism fundraiser it had planned after it was discovered that the charity involved believes that vaccines trigger autism.11  No matter how much evidence disproves their claims, those that believe that vaccines cause autism will continue to spread misinformation, muddying the waters for others.

Internet parenting boards abound with the misconception that vaccines cause sudden infant death syndrome (SIDS).  SIDS, also referred to as “crib death,” looms as every new parents’ worst nightmare: a seemingly healthy baby goes to sleep one night and never wakes up.  The vaccine most often blamed is the DTaP (diphtheria-tetanus-acellular pertussis) since it is first given to infants at 2 months, with booster shots at 4 and 6 months.  However, many studies have come to the same conclusion: infants receiving the DTaP shot are not at increased risk for SIDS.12   In fact, many studies show that the risk of death from SIDS is decreased following DTaP vaccination.

Lastly, one of the most frustrating misconceptions is that, if you are vaccinated, you should be protected and therefore it doesn’t matter if others do not vaccinate.  YES, IT DOES MATTER.  First, some people do not respond to vaccination.  For example, if 100 children are given the MMR vaccine, on average 95 kids will respond to the vaccine and become protected from measles, but 5 will not.13  Unless every child gets a titer (antibody) test after every vaccination, we do not know who these vaccine non-responders will be.  Second, there are immunocompromised individuals in our society that cannot be vaccinated, and newborns that are too young to be vaccinated.  In addition, the immune systems of the elderly make them susceptible to disease yet often times not responsive to vaccination.  We want to protect these people who cannot be immunized through herd immunity.  If an unvaccinated individual is surrounded by a population of vaccinated individuals, the pathogen cannot spread through the population (herd) and the unvaccinated individual is protected (an illustration of this concept can be found here: http://www.historyofvaccines.org/content/herd-immunity-0).  However, if too many unvaccinated individuals make up the population, the pathogen is able to spread from person-to-person, and protection for these individuals is lost.  Recent outbreaks of measles in New York and California are due to people not vaccinating and a loss of herd immunity.14, 15

This brings us back to Captain America.  Yes, polio is gone from the United States, but it still exists in the world.  The last imported case caused by wild poliovirus into the United States was 21 years ago.16  Not many people realize that Iraq was also polio-free for many years, 14 to be exact.  Now polio has returned to Iraq via travel from Syria.17  Don’t let the United States be Iraq.  Get vaccinated.


  1. http://www.cdc.gov/FLU/PROFESSIONALS/vaccination/
  2. Wakefield, A., et al. 1998.  Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children. The Lancet. 351: 637-641.
  3. Reviewed in: Wilson et al. 2003. Association of autistic spectrum disorder and the measles, mumps and rubella vaccine. Arch. Pediatr. Adolesc. Med. 157: 628-634.
  4. http://briandeer.com/solved/gmc-charge-sheet.pdf
  5. Retraction—Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children.  2010.  The Lancet. 375: 445.
  6. http://briandeer.com/solved/gmc-wakefield-sentence.pdf
  7. Schechter, R., and J. K. Grether. 2008. Continuing increases in autism reported to California’s developmental services system: m:  ercury in retrograde. Arch Gen Psychiatry. 65:19-24.
  8. http://www.nbcnews.com/id/16614865/ns/us_news-life/t/woman-dies-after-water-drinking-contest/#.U0cgjtgnK9I
  9. http://www.webmd.com/children/vaccines/features/robert-sears-alternative-vaccine-schedule
  10. DeStefano, F. et al. 2013. Increasing exposure to antibody-stimulating proteins and polysaccharides in vaccines is not associated with risk of autism. J. Pediatr. 163: 561-567.
  11. http://www.usatoday.com/story/news/nation-now/2014/04/07/chilis-vaccine-autism-fundraising/7411905/
  12. Vennemann et al. 2007. Do immunisations reduce the risk for SIDS? A meta-analysis. Vaccine.25:4875-4879.
  13. http://www.cdc.gov/vaccines/pubs/pinkbook/meas.html
  14. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6236a5.htm
  15. http://www.scpr.org/news/2014/03/18/42870/majority-of-states-measles-cases-were-unvaccinated/
  16. http://www.cdc.gov/vaccines/vpd-vac/polio/dis-faqs.htm
  17. http://www.nytimes.com/2014/04/08/world/middleeast/polio-spreads-from-syria-to-iraq-causing-worries.html