I saw a kid with chickenpox...

I saw a kid with chickenpox. This isn't that unusual, as I'm a pediatrician and an infectious diseases specialist. Pediatricians have been coming home and saying "I saw a kid with chickenpox," to their spouses for a long, long time. It's less common now, because we have a safe, effective vaccine that prevents infection with varicella, the virus that causes chickenpox. Children get two shots -- the first at 12 months and the second at least three months later. In exchange for this, they get lifelong immunity against a disease that used to affect essentially all kids.

There are a reasonable number of people, some pediatricians included, who think that the varicella vaccine is superfluous. Why give a shot to prevent something that we all had as kids? After all, it didn't kill us, right? Well, before the vaccine was licensed in the United States, there were about 11,000 hospitalizations and 100 deaths per year due to chickenpox. These are relatively small numbers when compared to the size of any year's birth cohort, though that calculus changes pretty drastically if your kid is one of the 100. The vaccine has drastically decreased these numbers, though there are still cases, including severe ones. These may occur among immune compromised people, children who are too young to have received the vaccine, or those whose parents or pediatrician decided to forgo this protection.

Which brings us to the kid I saw. She was a beautiful two year-old with the classic dots of chicken pox studding her pale skin. They had passed the "dew drop on a rose petal" phase and were crusted over already, indicating that her immune system had the virus pretty well under control. What was less under control was the Streptococcus bacteria that had taken advantage of her damaged skin barrier to invade first the soft tissues of her neck and later her bloodstream. That's why we met in the intensive care unit, where a ventilator did her breathing, where Sharpie lines on her skin demarcated the spread of her infection since her arrival, and where her father told me that she was up to date on her vaccines. It was just that her pediatrician didn't give her the chickenpox shot at the 1 year-old visit.

When you sign up to be a pediatrician, you agree to sometimes argue with parents, to push and cajole and manipulate so that parents trust that, yes, even though the grandmother says to put the newborn baby on her stomach to sleep that it really truly is safer on the back. We ask questions about car seats and smoke alarms and guns in the house, all in the name of preventing tragedy. There are so many things that we can't vaccinate our patients against. If I had a child abuse vaccine, a car crash vaccine, a heartbreak vaccine -- I would use them all. It turns out that we only have a handful. So why, then, was I picking up the pieces of this family whose daughter was fighting bravely against one of the few things that we actually know how to prevent?

Measles outbreak in U.S. started by unvaccinated child.

The measles outbreak that started in San Diego was imported by an unvaccinated 7 year old boy who visited Switzerland. The MMWR early release report is here. There have been at least 11 secondary cases, and a large-scale public health response has been required to deal with the many contacts of this child who are also unvaccinated because their parents used "personal beliefs exemptions." How many of these does it take before we do away with these ridiculous exemptions? Parents who refuse vaccines not only put their own children at risk, but also risk the lives of children who have to rely on herd immunity for protection (immunocompromised children who cannot receive the live-attenuated measles vaccine and those too young to be vaccinated).

Paul Offit on the Poling Case

Paul Offit has a typically brilliant op-ed piece in today's New York Times. He takes a logical look at the Vaccine Injury Compensation Program and the potentially destructive fallout of the recent and highly publicized Poling case. An especially compelling (and often missed) point is the harm that cases such as this may do to autism research and, indirectly, to affected children. Every dollar spent trying to prop up the discredited vaccine-autism link is a dollar diverted from research that might lead to a better understanding of a complex disorder.

Note: There is also the obligatory asinine response from David Kirby at Huffington Post.

CDC vaccine safety site

The CDC has a new vaccine safety site. This is a much better place to get scientifically valid information than, for example, a Republican presidential candidate.

Avery and the pneumococcus

I gave a lecture on Streptococcus pneumoniae (pneumococcus) in our global antimicrobial resistance course today. Despite more than a hundred years of work, the pneumococcus remains a major cause of morbidity and mortality worldwide. We have vaccines, we have effective antibiotics (fewer and fewer…), yet pneumococcal infection still kills about a million kids every year.

Here’s something that I do when I want to feel small: I look back at the papers that Oswald Avery published on the topic of the pneumococcus between 1915 and 1946 in the Journal of Experimental Medicine. (Thanks, JEM, for opening up your archive back to the very first issue!). Not only is the paper defining DNA as the transforming substance in there, but nearly everything that we understand about the pneumococcus was done or predicted by Avery. The carrier state, capsular polysaccharide (and the fact that one can diagnose pneumococcal infection by detecting it in the urine), autolysis, hydrogen peroxide production, discovery of C-reactive protein, and how to make a conjugate vaccine: it’s all there. Our best diagnostics and vaccines are still offshoots of his work.

As with any great scientist, he did not work alone, and many others have contributed to advancing the field, but I remain in awe of Avery.




Dochez, A.R., Avery, O.T. (1915). THE OCCURRENCE OF CARRIERS OF DISEASE-PRODUCING TYPES OF PNEUMOCOCCUS . Journal of Experimental Medicine, 22(1), 105-113.