The CDC yesterday updated their report on recent cases of measles. In 2000, thanks to the aggressive vaccination program, measles was declared eradicated from the US. There continued to be on average 63 cases per year from 2001-2007 due to imported cases from outside the US. To ironically quote Jim Carrey from the aptly titled, A Series of Unfortunate Events – “Then the unthinkable happened.”

The anti-vaccination movement was given a boost by actress Jenny McCarthy, who was convinced that vaccines were responsible for her son’s apparent autism. She was later joined in her crusade by her boyfriend, Jim Carrey. The movement had already been gaining some traction over false fears that thimerosal in vaccines (although mostly removed by 2002) was linked to autism. Such fears had already caused a drop in vaccination rates in the UK with subsequent measles outbreaks. Now these irrational fears were coming to the US, helped along by scientifically-illiterate pretty-people.

Due to the high-profile nonsense being spread by the antivaccinationists and the “mercury militia,” vaccination rates in the US have now dipped also (although not nearly as much as in the UK). Overall rates remain high, but there are pockets of low vaccination rates in communities where vaccine fears have spread. Such communities have dropped below the herd immunity level of vaccination and are susceptible to outbreaks.

The latest numbers from the CDC show that 131 cases have been reported in the US so far this year – extrapolating that is about 4 times the rate of the previous seven years. Of these cases 15 were hospitalized and no deaths were reported. Most importantly, 91% of the cases were in those who were unvaccinated or had unknown vaccination status. Only 9% were in those known to be vaccinated. These statistics show two things – it is clearly the drop in vaccination rates that is resulting in the return of this disease; and because the vaccine is not 100% effective, even those who do get vaccinated are at increased risk of infection because of those who choose not to. We all depend upon and benefit from herd immunity – so the Jenny McCarthy brigade has caused harm to innocent bystanders.

The idiocy of antivaccinationists partly rests upon the modern luxury of never having had to live through the horrible epidemics of the past. I wonder how much the current generation will have to suffer through before they get it.

And I will say it again – if Jenny McCarthy is going to put her own “mommy instinct” before the consensus of scientific opinion, and exploit her dubious celebrity to champion anti-science, then she is going to have to take responsibility for her actions. The way I figure it, so far there are at least 68 measles cases on her tally sheet, and the number is growing.