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Ask, Acknowledge, & Advise: Tips and advice you can use
   October 2013
In This Issue
Answering your questions
Preparing for the flu
Vaccines in the news
What we're reading
Exciting new immunization resources
TopGreetings!

 

Welcome to the October 2013 "Let's Talk Vaccines" newsletter. 

Below you will find our usual features, along with the details of an exciting new film about vaccine hesitancy and some useful immunization related web apps.

While our study is nearing its conclusion, we encourage you to contact us with comments or questions as they arise.  We're here to serve you!

 

Best wishes,

David Grossman, MD, MPH

Group Health Research Institute

"Let's Talk Vaccines" study principal investigator

  
   
Answering your questions

  

Below is a response to a question submitted during a recent training.  We encourage participants in this study to submit their questions whenever they arise.  We will share some answers here, but all are available on our study website.
 
A parent of a 4-year-old in cooperative preschool is concerned about the benefit of starting Hib vaccine at 4 years. Asks if there is decreased risk for Hemophilus infection for the year between age 4 and 5?  In addition, is there any benefit to initiating pneumococcal vaccine in a healthy child at this age?

Vaccination against infection by Haemophilus influenzae type b ("Hib") has been one of the most pronounced success stories of the vaccine era. Hib was once the most common cause of bacterial meningitis and epiglottitis in children under five years of age (as well as a significant cause of septic arthritis, cellulitis, pneumonia, and other invasive disease), with roughly one in every 200 children experiencing at least one invasive Hib infection. Today, the incidence of invasive Hib disease has fallen by well over 99% from an estimated 20,000 cases annually in the U.S. in the 1980s, and the resulting change in the practice of pediatric medicine has been among the most profound of our lifetimes.

 

One of the hallmarks of H. influenzae type b infection in the pre-vaccine era was the fact that infection was markedly age-dependent, with over 90% of all invasive infections occurring in children less than five years of age. At that time, the incidence of Hib disease peaked in the middle of the first year of life (thought to be associated with the decline of maternal antibodies acquired transplacentally or through breastfeeding). Roughly two-thirds of cases occurred in children younger than 18 months of age; however, the incidence of disease remained elevated (though decreasing steadily) through the first five years of life.

  

In the pre-vaccine era, it was thought that most children acquired immunity by 5-6 years of age as a result of asymptomatic infection with the Hib bacteria . Whether this process continues today is not known. However, because vaccination is known to decrease the rate of asymptomatic carriage of Hib, it is assumed that there is today a lower likelihood of exposure to the Hib bacteria ... and it could be further assumed, therefore, that there would be less opportunity to develop such an asymptomatic infection.

  

Unlike Hib, which is today an infrequently-isolated organism (only 35 cases of culture-confirmed invasive disease were reported in the United States in 2009), Streptococcus Pneumoniae remains prevalent. Each year in the U.S., there are over 50,000 cases of Pneumococcal bacteremia, between 3,000 and 6,000 cases of Pneumococcal meningitis, and an estimated 175,000 hospitalizations from Pneumococcal pneumonia. Prior to the routine use of the Pneumococcal vaccine in infants, there were an estimated 17,000 cases of invasive disease each year in children younger than 5 years of age.

  

The incidence of invasive Pneumococcal infection in children has also improved greatly since the introduction of the Pneumococcal Conjugate Vaccine (PCV); however, the decline has not been nearly as dramatic as was seen for Hib. The overall incidence of invasive Pneumococcal infection fell by less than 80% over the first decade of PCV use. This does not mean that the vaccine was ineffective; the incidence of invasive disease caused by the seven strains of Pneumococcus contained in the vaccine declined by 99%. However, this decline was in part offset by an increase in invasive disease caused by serotypes that were not contained in the PCV7 vaccine (many of these are included in the newer PCV13 vaccine).

  

More important, however, is the fact that the vaccine was far less effective at preventing non-invasive Pneumococcal disease (such as acute otitis media). In one study of vaccinated children, the rate of ear infections caused by vaccine serotypes had fallen by less than 60%. This means that the strains of Pneumococcus that were once a common cause of bacteremia and meningitis haven't disappeared - they're still at large in the community, and likely show up in your office all winter long. The children that have been vaccinated, of course, are unlikely to get anything other than minor disease from these strains ... but kids under age 5 who haven't been vaccinated and get exposed to one of these Pneumococcal serotypes are still at risk for development of bacteremia and meningitis (just as was the case 15 years ago).

   
 

  

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Everybody's Business

On September 16th, Seattle Children's Hospital screened the documentary Everybody's Business, which profiles the vaccine debate on Vashon Island, a community with exceptionally high hesitancy and exemption rates.  The screening was very well-attended and was followed by a rich and compelling panel discussion (panelists included Doug Opel, Wendy Sue Swanson, and Ed Marcuse of Seattle Children's Hospital; Celina Yarkin, a Vashon vaccine advocate featured in the documentary; and Janna Bardi from the Department of Health).

The documentary and discussion underscored several points, all focusing on communication and the need to re-imagine how parents receive information about vaccines.  Recognizing that parents, including those who refuse or are hesitant to vaccinate, truly want what is best for their children, we have to find a way to erase the vitriol around vaccines and revisit the assumptions that are implicit in the vaccination schedule and how we communicate about it (e.g. that parents understand the schedule and why we vaccinate). 

Furthermore, the ever-present tension between individual liberty and public health remains a challenge with respect to vaccines, and decisions must be made about when and if public health should be forceful, or if adequate protection is best achieved by better informing people of the benefits of vaccines and the risks of disease.

If interested, follow this link to watch the 20-minute documentary.  The password is EB_preview.

 

Vaccines in the news    Bird2
  • The Associated Press and several other publications are relaying good news from the CDC: more children than ever got vaccinated against the flu last year.  
  • At several points in the past, this newsletter has discussed the Parent Attitudes Concerning Vaccines, or PACV, survey developed by Dr. Doug Opel at Seattle Children's Hospital.  The survey has proven to predict vaccine hesitant behaviors, and is now being covered popularly, for instance by HealthDay News.

 

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What we're readingBird4

 

Below are three articles currently informing our work: 

 

A new Pediatrics study suggests that nonmedical exemptions may have been one of the factors in the 2010 California pertussis epidemic.  While the study cannot show causation, only associations, the authors did demonstrate that Census districts with an exemption cluster (a statistically significant geographical grouping of exemptions) were 2.5 times more likely to to be in a pertussis cluster.

A recent PLOS ONE study delves into the origin of the connection between 'conspiracist ideation' and the rejection of science.  Relevant to this study, the authors found that conspiracist thinking is more common among the political left (e.g. vaccine hesitancy amongst affluent liberal populations), conspiracist thinkers tend to seek out attitude-consonant perspectives, and that conspiracists are three times more likely to reject vaccinations.

Consistent with previous academic findings, and running contra to the dominant belief that social media is a purveyor of unsound information and unfriendly to vaccines, the AAP reports that "the tone of the majority of posts on Twitter about vaccines was positive or neutral, and that most contained medical information substantiated claims."

 


New resources

Vaccine map apps!
 
There are two exciting new web applications created by Boston Children's Hospital relating to the flu.  The first, Flu Near You, tracks flu activity, creating dynamic, real-time representations of flu activity.  The second, the HealthMap Vaccine Finder, allows users to search for flu vaccine dispensing sites in their area.

        

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