From Katelyn Jetelina and Kristen Panthagani, MD, PhD (Your Local Epidemiologist)
The measles outbreak at a Florida elementary school has grown to 8 cases and counting.
We have measles outbreaks all the time (although the rate is increasing due to vaccine hesitancy), but this one came with a new controversy. The Florida State Health Department released a letter with a surprising new recommendation that contradicts standard of practice guidelines for measles outbreaks in two big ways:
- Isolation. It stated that unvaccinated kids who were exposed to measles could continue to attend school. This is unprecedented. Those with no prior immunity need to isolate for 21 days.
- Vaccination. It failed to recommend kids without immunity get vaccinated. Many parents don’t know that unvaccinated kids can still get protection from a vaccine within 72 hours of exposure. (Also, the standard of care is that if they get vaccinated within 72 hours, they can return to school as long as they don’t develop symptoms.
The FL letter tries to justify the decision to let exposed kids without immunity go to school by arguing that the vaccination rates in Florida are high. It’s true that 90% of FL kindergartners are vaccinated, which is high. But not high enough—because measles is so contagious, the threshold for herd immunity against measles is 95%. This means there are pockets in the school, other schools, and a community that measles could burn through. Check out this figure showing the percentage of kindergarteners with the MMR vaccine:
