Sunday, November 7, 2010

Vaccine Awareness Week

A couple of weeks ago, NVIC and Joseph Mercola announced a Vaccine Awareness Week for November 1-6, 2010.  Science-blogger, Orac put out a call to other science and sceptical bloggers to co-opt this week for vaccine awareness, just not in the way that Mercola and Barbara Loe Fisher (BLF) intended.  People like Mercola and BLF sell fear; it's their bread and butter, their pay check, literally.  They don't actually present vaccine information, but rather pure deception.  A number of us wish to counter this with facts, but since we hold ourselves to a higher standard of information, our facts and evidence can appear apathetic and tedious compared to their emotional, yet misleading rhetoric.  But as a parent trying to make vaccine decisions for your children, you must ask yourself which is more important to make truly informed decisions.

I had hoped to present a detailed list comparing adverse vaccine reactions and corresponding disease complications this week but time constraints prevented that.  However, Science-Based Medicine has a partial list of reactions that accompany both disease and corresponding vaccination.  A Photon in the Darkness also ran the numbers for the probability of measles infection as they exist currently.  This should help to put some real risks into perspective.

I came across a post on a forum that, I believe, sums up what parents are concerned with:
"I actually don't buy into the idea that any one vaccine causes autism. I know science is revealing a certain susceptible group that have genetic issues which, when combined with a load of vaccines, have triggered it.
That darn Wakefield study had to go and put a blemish on the MMR vaccine, so now in the back of my mind, I can't help but be haunted by it. Plus, all of the parents who swear to have their children get "lost" after it. It's just so scary when it comes to your babies and it gets really personal. I'm sorry if I get so angry sometimes, it's only out of fear and frustration."
To paraphrase Dr. Paul Offit, it is easy scare parents but nearly impossible to unscare them.  So even though the science has spoken, so to speak, that MMR, thimerosal and to some extent, vaccines in general, do not increase the risk of autism or adverse neurophysiologic outcomes, anti-vax organisations are still trying to beat this dead horse.  The result is that many parents are thrown into a stasis regarding vaccine decisions for their children, either delaying rather important ones or not vaccinating at all.  So let me address some of those reasons why and also to present some resources to use and not to use when making vaccine decisions.

Vaccines Versus the Vaccine Schedule
Looking at the CDC Recommend Infant Vaccine Schedule is daunting.  One of the criticisms I hear is that it is "one size fits all".  Well yes, it is and this is why; it is a recommendation for public health and as such, is designed for what is in the interest of the majority.  Such a schedule attempts to take all risk factors into account, has determined what ages will have the best 'catchment', or success at vaccine uptake, along with efficacy, and ages at which vaccine preventable diseases pose the greatest risk.  Contrary to some belief, the paediatric vaccine schedule has been tested for safety and efficacy (scroll down halfway for list of studies).  Numerous vaccine experts have developed the schedule to assist physicians and take the guesswork out of their vaccine recommendations as it addresses the collective of potential exposures.

Where I believe the problem lies, is that several vaccines have been added over the past 15 years so parents are given the impression that a relatively minor childhood disease such as hepatitis A is on par with the more serious hepatitis B disease, or chicken pox is on par with measles or rubella, or rotavirus disease is a scourge on par with Haemophilus influenzae b (Hib) disease.  Don't get me wrong, people in developed countries do suffer from these diseases that can have serious complications.  It comes down to risk analyses, which is not something that most parents are equipped to undertake.  This is where the 'kindly', 'sympathetic' and 'passionate' self-proclaimed experts like to insert themselves.  I have criticisms of and concerns with the CDC schedule, which would take several blogposts to outline; but that doesn't mean that Dr. Bob Sears, Dr. Jay Gordon or Jenny McCarthy should be dictating public health decisions and issuing proclamations.  So what can parents do?  Well for starters, don't throw the baby out with the bath water.

Speak to Your Doctor
It sounds very evasive but doesn't have to be.  You have undoubtedly heard stories of paediatricians tossing clients out of their practices for refusing to vaccinate or refusing to vaccinate 'on schedule'.  And I'm sure there are physicians that would do that on that basis alone, but I also don't believe that we are getting the full story for most cases.  Not vaccinating is only part of why physicians feel the need to dismiss parents from their practices.  The AAP's official policy is for physicians to work with families that are either concerned about vaccines or refuse them all together.

Broach the subject in a respectful manner and develop a partnership with your physician.  Call them ahead of your first well visit and schedule a consult (preferably without children), be sure to let the office know the reason for the consult.  You are demonstrating respect for your physician's time and giving yourself an opportunity to work with your physician instead of at cross-purposes. You aren't going to be well-received if you arrive at a scheduled well visit waving your copy of The Vaccine Book and telling your physician, "Well Dr. Bob says so."  Don't become so wedded to a particular course that you dismiss sound advice from your own physician, be flexible.  Take advantage of combination vaccines that will provide your infant with the protection they need in a timely fashion and reduce the number of jabs and vaccine excipients.  Ultimately, your children's healthcare decisions are your own but consulting with your physician on vaccines may reassure you.

Herd Immunity
You have undoubtedly read about herd immunity and how important it is to reduce or eliminate transmission of vaccine-preventable diseases.  It is also referred to as 'community immunity', for those who don't wish to be equated with cows.  In any term, it is real and irrefutable; based upon several factors, we know what levels of vaccine uptake are required to reduce or interrupt disease transmission.  But to be perfectly honest, I don't care to use the herd immunity argument as an inducement for vaccine uptake even though it is a valid argument and very true.  We are inherently selfish creatures, particularly about our children.  When one who is concerned about vaccines is being ramrodded with 'you need to do this for the protection of those that cannot get vaccinated', it tends to shut down the discussion and heels get dug in, even though it is a technically correct point.  We are driven to consider our own children's safety first.  While herd immunity is important, for you as a parent, protecting your own child is more important.

In order to refine this argument, I will use a parent's concern that I just came across; she wanted to know what her child's risk for Hib disease was now.  That risk estimation is 0.13 - 0.5/100,000 in children less than 5 years old depending upon the survey and geographical area, but the risk is higher in children less than 2 years old.  The risk is higher in unvaccinated children with an attack rate of ~3.7% in children less than 2 years old.  Prior to mass vaccination with Hib, the disease incidence was 1/200 children less than 5 years old with 5% mortality and 15-30% left with permanent complications and that is even with prompt and effective treatment.  So this is a very clear case of the reduction in illness, permanent injuries and death as a direct result of vaccination and herd immunity subsequently created.  The risk has been dramatically reduced, to the tune of 96% but even a brief interruption in vaccine uptake can result in disastrous consequences.

I prefer to emphasise that herd immunity also assumes equal distribution of susceptible people.  This means that a non-immune person, for whatever reason, is well-surrounded by immune people, creating a fire-wall of sorts.  The most recent estimate of 19-35 month old children that aren't vaccinated is ~1%.  However, that is just for complete vaccine refusal; vaccine coverage estimates for the individual vaccines are highly variable by vaccine and geographical area.  Due to the collection methods of this survey, it is likely that the proportion of vaccine refusers stand at a higher rate than reported.  So I will use the 1% as a minimum reliable estimate for vaccine refusal in the U.S.  Using the birth cohorts from the MMWR report, that is representative of ~10,692,000 children.  One percent of those are completely unvaccinated is ~106,920 children.  Add to that:

769,800 (7.2%) children 19-35 months old were not vaccinated for polio.
1,069,000 (10%) children 19-35 months old were not vaccinated for MMR.
844,600 (7.9%) children 19-35 months old did not receive the primary Hib vaccine series.

This doesn't include those younger than 19 months or older than 35 months and those who are undervaccinated or with waning immunity.  Now to put this into context; refer back to how herd immunity theory assumes equal distribution of susceptibles.  Not only is there a growing number of susceptibles, but they are geographically clustering.  This pattern seriously undermines the strength of herd immunity.  Even though overall vaccine uptake is high, it is too variable to be relied upon for protection of one's un- or undervaccinated children.  Since ideologically like-minded parents do tend to aggregate, such a situation can and does lead to large clusters of unvaccinated children that your child could be living in the midst of.  A parent needs to start thinking about their own children and what they can do to protect them because herd immunity should not be relied upon.  Think of it as enlightened self-interest in that while vaccinating your own child helps the "herd", more importantly, it protects your own child.

Information Resources
It is important to vet your sources, particularly those that can be found on the internet since that is where most parents go to obtain information about vaccines now.  Science-Based Medicine just posted an analysis of two studies that evaluated population-level perceptions on the H1N1 vaccine, dominant sources of vaccine information and the effectiveness of anti-vaccine tactics.

Regarding the H1N1 vaccine:
During the survey period, 23.4% of Canadians considered the vaccine safe, compared to 41.4% who indicated it was unsafe, and 35.2% who expressed no opinion.
Vaccine information sources that dominated during the survey period:
But based on the methodology used, articles questioning the safety of the H1N1 were circulated widely, and anti-vaccine articles and sources dominated.
And finally, the impact of anti-vaccine websites on perceptions of readers:
The authors found that viewing anti-vaccine material for only five to ten minutes increased the perception of risk of vaccination, and decreased the perception of risk of omitting vaccines, compared to viewing neutral websites. It also lowered vaccination intentions.
Obtaining information from the internet requires some filters to help establish the potential credibility of the site.  Some websites have become very savvy and sophisticated so that it can be rather difficult for the layperson to identify them as anti-vaccine websites.  To give you a couple of examples, the International Medical Council on Vaccination looks slick and professional.  But behind the scenes are the usual suspects such as Sherri Tenpenny and Joseph Mercola, along with contributors with formidable letters after their names who want to give you the impression that legions of healthcare professionals and scientists are united in their efforts.  Read the articles, they are bush-league, overwrought and completely unreferenced opinion pieces.  Citations to the scientific literature and the proper interpretations of studies are crucial for establishing credibility.  Another website is the National Vaccine Information Center or NVIC.   This site is very much the same as the aforementioned website.  They have some kernels of factual information but these are obfuscated by unreferenced opinion pieces and misrepresented statistics.

As a general rule, be very leery of websites and/or self-proclaimed vaccine experts that wish to sell you something, whether that be books, products or services and rely upon testimonials.  Verify that they provide references for their information and if so, are the references from reputable sources (i.e. legitimate peer-reviewed journals or government publications) and do they represent these sources accurately.  If you are unsure of information that you have received or just have questions to ask about vaccines, please feel free to visit our forum here (you may do so anonymously) and we would be happy to answer your questions.

Some reputable resources that I recommend are:
The Pink Book (Epidemiology and Prevention of Vaccine Preventable Diseases)
The Immunization Action Coalition
The CDC: Some Common Misconceptions
The Institute of Medicine:  Immunization Safety Review Reports
The CDC: Vaccines and Preventable Diseases
The CDC: Morbidity and Mortality Weekly Report (MMWR)
Johns Hopkins: Institute for Vaccine Safety
The CDC: Vaccines and Immunizations
The FDA: Thimerosal in Vaccines
Center for Infectious Disease Research and Policy (CIDRAP)
The CDC: Vaccine Safety
The American Academy of Pediatrics (AAP): Red Book (subscription only)
The College of Physicians of Philadelphia: The History of Vaccines
The Children's Hospital of Philadelphia (CHOP): Vaccine Education Center


  1. followed over from countering-firstly wanted to say-I love when you comment over there..:)

    This is an excellent post-excellent..but, as I was saying over on countering this morning..all the info in the world isn't as attractive as magical group thinking...sigh..

  2. Thank you Kathleen. I was targeting the 'fence-sitters' in this blog. There is that small, albeit vocal group that you are talking about that can't be reasoned with or informed so I just counter their information. I prefer to spend time addressing the concerns of parents that are confused about vaccinations and all of the misinformation that they have heard. This is the group that can be reached with understanding and solid information.