Archive for the ‘vaccines’Category

Progress on Polio in Africa?

From the latest CDC Morbidity and Mortality Weekly Report: “Progress Toward Interrupting Wild Poliovirus Circulation in Countries with Reestablished Transmission — Africa, 2009-2010”

There are only four countries where polio is still “endemic” — Afghanistan, Pakistan, India, and Nigeria. Combined the four endemic countries have about 23% of the world’s population, though to be fair polio is only endemic in some portion of each country.

But the actual definition of “endemic” may not match with lay assumptions about that term. For polio, endemic countries are defined as those where transmission has never been broken. So a country where polio has been reintroduced — and is now spreading on its own, without the need for additional introductions — is by definition still not endemic. Thus, there’s essentially a three-tiered system: a) endemic countries, b) countries with reestablished transmission, and c) countries without established transmission, which may have sporadic outbreaks from imported cases or from vaccine-derived polio.

The CDC report linked above provides an overview of polio in African countries. Between 2002 and 2009 several dozen previously polio-free countries had outbreaks of polio from strains imported from India or Nigeria. (The strain of polio in each outbreak is genetically typed, which means we can determine which known strain the new one is closest too, and thus from whence the outbreak came.) Of those countries, four–Angola, Chad, Democratic Republic of the Congo (DRC), and Sudan–had persistent transmission (more than one year) after re-importation of polio that occurred before 2009. One of the milestone of the Global Polio Eradication Initiative (GPEI) was that polio transmission would be interrupted in those four countries by the end of 2010. The conclusion of the MMWR report is that it has been stopped in Sudan, but not Angola, Chad, or DRC.

28

03 2011

Review: "The Panic Virus"

Review of The Panic Virus, by Seth Mnookin. Simon & Schuster Jan 2011 (Available at Amazon) [Disclosure: I got a free copy of the Panic Virus from a friend who has a friend that works at the publisher — I wasn’t given the copy specifically to write a review, but it’s still probably better to disclose I didn’t pay for the book.]

Seth Mnookin’s The Panic Virus starts and ends with two stories of parents whose seemingly normal children come down with a serious illness. He describes their children before the episodes, and then their dread as they go downhill, are hospitalized, and fight for their lives. These stories intentionally parallel the narrative of the vaccines-cause-autism movement — “our child was normal, then he got the vaccine, and then he got autism, so it must have been the vaccine.” However, Mnookin’s carefully chosen stories don’t support the anti-vaccine movement; they do just the opposite and make you feel heartsick for the children affected by vaccine-preventable diseases.

Mnookin knows how to tug on heart strings, and how to get his readers riled up, so it’s a good thing that he comes down strongly pro-vaccine. His case studies are selected for emotional value, and they illustrate how a thoughtfully written narrative can humanize statistics about disease outbreaks and the danger of the anti-vaccine movement. But I approve of Mnookin’s tactics ultimately because his stories are true — vaccines save lives, and much harm has been done by the spread of unfounded fear.

That said, Mnookin’s book isn’t at all a fearmongering tale of what will happen if you don’t vaccinate your child — the bookend stories are just that, and he could probably have included a few more narratives throughout without stretching it. For the most part his book is a sober narrative of a social movement that goes back to the earliest vaccines, but has only come to nationwide fruition with the rise of the Internet.

Mnookin chronicles the development of early vaccines, and, to his credit, spends a good deal of time on what was done badly by the scientists and advocates. The Cutter Incident is there,  along with the 1976 swine flu vaccine. Mnookin doesn’t mince words in describing injuries that have been caused by vaccines, and at many times I found myself cringing and thinking “why weren’t better systems in place earlier?” and “they really should have done more”.

This willingness to confront unpleasant truths is a strong point for the Panic Virus, and it also gives Mnookin an opportunity to introduce the safety innovations that stemmed from each incident, all while setting the stage for the anti-vaccine movement. Another strength is that The Panic Virus also offers compelling humanizations of many of the parents of autistic children who have been involved in the anti-vaccine movement. Their despair at seeing their children suffer, their ostracization in a society where autism is not accepted, their occasionally callous treatment by physicians who have no easy answers to offer — all of this makes it impossible not to sympathize with them.

For the most part, Mnookin doesn’t present parents as the villains of his story. That role is reserved for shoddy physicians, scientists and pseuodoscientists, and most of all for journalists. Andrew Wakefield, Mark and David Geier, and journalist/author David Kirby all come in for harsh reckonings, along with many other “expert witnesses” for anti-vaccine lawsuits. This book left me quite depressed regarding the role of journalists and TV personalities in the whole fiasco. There has been so much bad reporting, and so little good.

While reading The Panic Virus, I kept thinking that its major shortcoming is a lingering uncertainty about its target audience. Is Mnookin writing for the uninitiated who want an introduction to where the anti-vaccine movement? Or is he writing a broadside for those already staunchly in the pro-vaccine community? There are sections where the rhetoric made me think it was the latter, while the majority of the book seems to be for those with little outside knowledge of vaccine science. Since Mnookin cautions so much against being led astray by charlatans who peddle fear with a thin veneer of scientific-sounding verbiage, I wish he had done a bit more to explain the science done in recent years on vaccine safety, thiomersal, MMR, and autism. I understand why an author writing a popular narrative would avoid trying to describe these subjects: they are incredibly complicated and divert the reader from the narrative. [Note that I haven’t read Paul Offit’s Autism’s False Prophets, which I understand might have a bit more of that.] And it’s not like good science writing is entirely missing from The Panic Virus. Some things are explained well, but overall there’s just a bit too much deference to the authority of  science and scientists for my tastes, especially for a book intended for lay audiences. It’s a good book, but not a great book.

I also wish Mnookin had provided a better counter-narrative in the second half of the book. Broadly speaking, the first half follows the development of vaccines and early vaccine injury scares (founded and unfounded), and the second half explores the rise of the anti-vaccine social movement. The second half is missing strong pro-vaccine characters, such as one or two scientists or policymakers who have been working to combat the anti-vaccine crowd. A lot of good research has been done to disprove fallacious claims, and to look for policy solutions aimed at decreasing opt-out rates on a state level, but none of that is here.

To date the anti-vaccine crowd has really won the narrative war: their message is simpler, and scarier, and has the added perk of being anti-establishment in appealing ways. The Panic Virus didn’t give me much hope that that would change soon — although the book itself is mostly a step in the right direction, combining a pro-science view with a few emotional narratives about vaccine-preventable diseases.

Our best hope is that eventually our scientific explanations of autism etiology will solidify a bit more, and coupled with much more demonstrably effective treatments, the snake oil appeal of the “cures” sold by the anti-vaccine movement will lose their charm. One theme of the Panic Virus is that the anti-vaccine movement arose because parents of autistic children weren’t getting the sympathy, explanations, and help they needed. Many factors including a lack of understanding by doctors and communities, isolation, weak scientific explanations, and a lack of viable treatments all created a situation like a field of dry grass. When a powerful idea — “vaccines cause autism” — arose and was amplified by the echo chambers of Internet communities, it ripped through the dry field like a wildfire, sowing panic and fear. And the fire still hasn’t been put out.

01

02 2011