I don’t agree with Daniel’s conclusions in his article in Slate about the measles “crisis” but he did his research and there are lots to chew on. You don’t have to agree with him to find this article thought-provoking.
There is one paragraph which everyone should read. It’s a celebration of science, and how it saved lives. (Daniel used this story for a different purpose: he argued that we never “eradicated” measles, and therefore, the anti-vaxxers could never have reversed some mythical victory.)
During the most recent, major wave of measles infection in the U.S., between 1989 and 1991, close to 56,000 people fell ill and more than 100 people died...The 1989–91 epidemic was large enough and deadly enough to cast light on two pressing problems: First, that a single vaccine dose was not sufficient to protect children, and second, that black and Latino children, especially those living in urban areas, were less likely to be vaccinated, and thus more vulnerable to the disease.
Efforts were made to address both issues in the years that followed. A second measles shot was recommended for all children, while the federal government ramped up efforts to provide free vaccination to high-risk groups. The plan worked. By 1994, vaccine coverage for measles was closing in on 90 percent. The number of cases reported every year soon dropped from the thousands into the hundreds, and then into the tens. It was in response to this decline that experts from the CDC announced that measles had been “eliminated” from the U.S.
It's a great example of finding the drivers behind the data, and executing actions that successfully changed the numbers.
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From the rest of the article, here are some useful tidbits:
- Vaccines work because of a phenomenon called “herd immunity,” which is a type of wisdom of the crowd. Diseases spread when people interact with each other. If both sides are vaccinated, then the risk of spreading is much, much lower. Thus, the higher the proportion of the vaccinated, the lower risk for everybody. The threshold desired by health authorities is 93 to 95 percent.
- In the past several decades, at a national level, the vaccination rate has stayed around 91 percent. So it is below the desired level but seems close enough not to cause alarm.
- Discredited research by a Dr. Wakefield ignited the anti-vaxxer movement. The publication of such research allows people to confirm their prior beliefs, and it often is hard to dislodge such beliefs, even when the research has been invalidated.
- In some localities, e.g. Somalis in Minnesota, the rate of vaccination has dropped drastically to below 50%. Those are isolated communities, and in aggregate, the level of vaccination has not changed.
- The number of measles cases while small has shown signs of increase. There have been triple-digit cases 7 out of the last 10 years, but only twice in the previous decade.
- The fatality rate of measles is extremely low, 11 deaths in 18 years, which is said to be similar to being killed by scorpions. Those who read Chapter 2 or 4 of Numbers Rule Your World (link) will recognize the need to think about the cost of errors.
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