Why did we have so many cases of measles in 2014? Bad luck, basically. The source was an unvaccinated person traveling abroad to a country where an outbreak has been raging for years, coming back, and being mis-diagnosed while being in a community with low vaccination rates.
Key facts to remember:
- The epicenter of 2014's outbreak was Ohio, not California. The "personal exemptions" that have people up in arms in CA are irrelevant.
- The US national rate of vaccination against measles has remained roughly constant for 10 years. Despite bad science, the Internet, bad celebrities, and various combinations of the above, the rate of measles in the US has varied by almost a factor of 10x year to year without the rate of vaccination changing.
- The measles vaccine - even when administered perfectly - is about 97% effective. This is one reason why your doctor will test your immunity and recommend a re-vax if you say that you are traveling to a country where measles is known to be active. Blaming anti-vax parents and religious objectors for the fact that a vaccine is not a light switch is ignorant; don't do that.
- Measles is stupendously contagious. It can do survival tricks that no other known virus can do, like remaining potent in microscopic suspended air droplets for hours. Given that immunities and vaccines are not perfect mechanisms, it should be unsurprising that people get sick from this virus. We should stop freaking out about that.