Once of the most polarizing of topics among parents is the vaccine debate.  To vaccine or not? Which vaccines? On what schedule?  Nothing seems to stir a strong emotional response among parents like the contentious arguments either strongly against or in favor of vaccinating your child.

So, as a parent concerned with looking out for the safety of your child, how do you navigate through all the literature and research to make the best decision?  Unfortunately there is a lot of biased and confusing information out there.

To reasonably consider vaccination, parents need to examine all sides of the issue. There are risks to vaccinating your child and there are risks to not vaccinating your child and, as parents, you need to weigh those risks in order to decide what you are more comfortable with. Research how vaccines work and why we use them. Research the risks associated with vaccines. Research the risk associated with the diseases you are vaccinating against. Research your child’s risk of exposure to the disease. The CDC maintains comprehensives pages on most contagious diseases and vaccinations. Read articles written from both sides of the debate. Then consider all of the information together. The more information you have the better decision you can make.

Things to Consider For Vaccinations:

Chance of exposure to disease: Do you travel on air planes? Do you travel outside the US? Does your child attend a school where many other children are unvaccinated? Do you interact with children or adults who have recently spent time abroad? Do you work in a hospital or other high risk environment? If yes, then your child is at a higher risk of exposure.

Chance of having a severe reaction to vaccines: Do you have a family history of severe allergic reaction to vaccine ingredients (i.e. eggs)? Has your child had a severe reaction to a previous vaccine? If yes, the risk of an adverse effect is higher.

Risk if he/she does get the disease: Does your child have asthma? Does he or she run high fevers? Is your child immune-compromised? Has your child been hospitalized for routine illnesses? If yes, the risk of your child getting sick may be higher than a healthy child.

Coping with an ill child: Do you have good health insurance? Can you take time off work to care your child? Is your caregiver willing to take care of a sick child? If the answer to all these is yes, then the impacts of a long illness may be lower.

On a scientific level, consider the following when trying to make your vaccination decisions:

Herd Immunity

In order to protect a community from disease, a certain percentage of the population needs to be vaccinated in order to keep the disease from occurring. When vaccination levels fall below this level, the disease will likely re-enter the community. The usual level quoted used is 90% immune (either through vaccination or previous infection), but the values vary from 75% up depending on how contagious the disease is (http://www.idready.org/slides/feb_concepts.pdf pg 31 – to see rates by disease). People who cannot be vaccinated either due to allergies or previous adverse reactions depend on the high rate of immunization to keep them from contracting these diseases.

What that means is that if 90% of your community is vaccinated against say measles, the chance of anyone contracting measles is very small. If the vaccination level falls below 90%, then the chance of the disease spreading through that community increases quite a bit. High vaccination levels when we were children reduced the incidence of the most of these diseases to almost zero. If your child is surrounded by other people who are vaccinated against the measles, his or her chance of contracting the measles is very small (he or she is protected because the others cannot transmit it). However, if you child is surrounded by people who are unvaccinated, the risk of contracting the measles is much higher as there are more people who can transmit it. The CDC published an article about the 2008 measles outbreaks in schools.

Vaccine Ingredients

Vaccines contain a variety of ingredients some of which have risks and some of which do not. If your child is severely allergic to eggs, then vaccines containing egg compounds might be very dangerous for your child. However, if your child tolerates eggs then there should be no risk to the egg compounds in a vaccine. Some of these ingredients are natural and some are synthetic, but neither label necessarily indicates that they are safe or unsafe. There is a lot of scary information out there that may or may not be scientifically accurate on both sides of the debate.

First of all, almost everything is a chemical compound. Water is a chemical compound (H2O) yet no one is afraid of letting their child drink clean water. Even breast milk contains a multitude of chemical compounds including fats and proteins which are essential for your baby’s development.

So being a chemical compound does not mean it is dangerous. Some chemical compounds are dangerous, such as mercury, formaldehyde, lead etc and as parents we should try to minimize our child’s exposure to these chemicals. But even with chemical compounds that can impact humans, it also depends on the dose. Even water is lethal if you drink enough of it. So when determining what is safe for your child, you need to think about how much he or she is being exposed to and for how long.

Then there are natural and unnatural compounds. There are many very safe natural compounds like aloe vera and water. There are also some very toxic natural compounds like lead, opium and dioxins. There are also safe synthetic compounds such as Tylenol and infant formula.

Which chemicals are safe and in what doses?  Mercury is a naturally occurring compound, but it is found in some vaccines as a synthetic preservative called thimerosal. There have been concerns over the amount of mercury young children are exposed to and consequently thimerosal has been removed from most vaccines for children. Read the  CDC page on mercury.

The amount of mercury in all the vaccines your child would receive from birth up to six months is about 1 microgram of mercury (I had trouble finding brands that even contained thimerosal anymore)

Assumptions:

3 Hib vaccines = 0 ug (none of the brands have thimerosal)

3 DTAP vaccines = 0.9 ug (I used the only brand that contains thimerosal – there are 2 other brands that contain none)

3 Hep B vaccines = 0 (none of the brands have thimerosal)

Source: list of vaccines and mercury levels by manufacturer.  They have info on mercury levels in all the flu vaccines too. (If you do not trust the FDA, then go to the medical journals that did the original research: try the Journal of the American Academy of Pediatrics)

So is that dangerous or not? Mercury is not the best understood chemical in infants as no one is willing to test the effects on their small child (rightly so) but it is a known neurotoxin. But as a comparison, a 6 oz can of albacore tuna contains about 60 micrograms of mercury.

The level of mercury exposure that is considered safe on a daily basis is 7 ug/kg/day for all sources of exposure. So if you have a 10 lb or 4 kg child, the daily exposure should be less than 28 ug/day. The more conservative estimate based on methylmercury (the kind typically found in fish) exposure would be 1.2 ug/day for a 4kg child. (The type of mercury in thimerosol is ethylmercury which is thought be less toxic than methylmercury since it breaks down very quickly).

Source: http://www.atsdr.cdc.gov/cabs/mercury/index.html#risk and http://www.fda.gov/Food/FoodSafety/Product-SpecificInformation/Seafood/FoodbornePathogensContaminants/Methylmercury/ucm115644.htm

You can find similar information on other ingredients in vaccines using the fda,gov, epa.gov and cdc.gov. Find out what brands your doctors office offers and then research the vaccine – find out how much mercury or formaldehyde or other ingredient of concern is in that brand before you decide what to do.

Weighing risk versus benefit for vaccinating your child:

Once you have all the information about the risks and benefits of vaccinating, you still have to make a decision. Vaccines are harder because there are both risks and benefits. When it comes to something like cigarette smoke, it is clear: do not expose your child to cigarette smoke as there is no benefit to exposing your small child to cigarettes. With other types of exposure you have to weigh all the different factors.

More reading

Vaccine Debate: Do Unvaccinated Children Really Put Others at Risk?  - Download for $1.99 from Mothering.com