Pediatric Associates of the NW Blogs

Parents’ Intuition is Often Just Plain Wrong About Vaccines

Jay S. Rosenbloom, MD, PhD
October 04, 2011 07:10AM

I am not a one-topic doctor.  As a physician, it is my mission to protect children from preventable injuries and infections and to nurture the healthy development of their minds and bodies. There are many children’s health topics that deserve attention but information in the news recently has made it necessary to get on my vaccine soapbox again.

A study published in the journal Pediatrics this week revealed 13% parents surveyed vaccinate their children using an alternate schedule.  Even many of the parents who were following the recommended schedule thought that delaying vaccine doses was safer.  There are many theories about what started and has fueled this loss of confidence in vaccines.  I think it is now more important to help families understand the science so they can filter out the rumors and myths.

When parents decide to vaccinate using an alternative schedule they typically cite one of two concerns.  Either they worry that a young infant’s immune system is too vulnerable and should not be exposed to the vaccines, or they worry that there are too many vaccines to safely be given at such a young age.

A child’s vulnerable immunity is in fact one of the reasons for giving vaccines at a young age. That’s when children are most susceptible to the diseases vaccines prevent.  If a mother has Hepatitis B and doesn’t know about it when she gives birth, the infant has a 95% chance of becoming infected (unless they get the birth dose of the vaccine). Likewise, prior to the HiB and Prevnar vaccines, the average age for bacterial meningitis was 15 months old (that average includes people of all ages), showing infants were the vast majority of those who suffered from the infections.

I understand why a parent would see the number of vaccines and think it seems like a lot to give an infant.  What most don’t realize is that all of the vaccines combined are about 5% of what was in the vaccines when they were first developed.  The number of injections is more but what is in them has been purified to a bear minimum.

Here’s why: vaccines are made using parts of viruses or bacteria to stimulate ones immune system to become immune to a disease without having to suffer the risks of an infection. When analyzing how challenging something is to the immune system, we count the number of different things it has to respond to (called antigens). A piece of one protein from the surface of a virus is one antigen.  When first created, the DTP vaccine (against diphtheria, tetanus and whooping cough) had about 3,000 antigens in the one injection.  Today the vaccine we use for these three diseases has between 4 and 7 antigens (depending on the manufacturer).  As a matter of fact, if you look at the total number of antigens in all of the vaccines combined it is about 160, way less than previously used and way less than what a child encounters naturally each day.

The number of antigens a child’s body sees due to vaccines is significantly less than the number a child’s body sees day to day. When an infant is delivered from the sterile environment of their mother’s womb they very quickly become colonized with countless bacteria.  We estimate that a typical child is exposed to 2,000-6,000 antigens each day, just through normal life experiences.  The recommended injections for a 2 month old include diphtheria, tetanus, whooping cough, HiB, Pneumococcus, polio and hepatitis B.  The number of different antigens challenging their immune system adds up to only about 39.

For a better understanding of what our bodies are protecting us from everyday see here.

Regardless of the number of needle pokes at any doctor visit, vaccines are not overwhelming, and they are not too much too soon.  Children’s bodies handle thousands of antigens each day, but the antigens they handle from vaccines protect them from potentially harmful and sometimes fatal infections at a time when they are often most at-risk for those infections.

I repeat, and will continue to repeat, vaccines are safe, they prevent terrible diseases and they save lives.  My own children have been given all of the recommended vaccines, I cannot give a higher recommendation than that.