Herd, as in "herd immunity," the concept being that the majority of vaccinated people protect the minority who aren't vaccinated, a kind of safety-in-numbers for your immune system. But what if the number in the minority starts to creep up?
The U.S. Centers for Disease Control estimates this year’s flu vaccine was effective about fifty percent of the time. But the vaccine was much less protective for older adults.
The CDC found that vaccinations against influenza types A and B were about 56 percent effective overall. But in people aged 65 and older, the vaccines only worked 27 percent of the time. But Rhode Island Department of Health director Doctor Michael Fine says that’s no reason NOT to get vaccinated.
I blogged earlier this summer about a pertussis (whooping cough) outbreak in Rhode Island and a growing number of cases throughout the country (see the latest from the RI Dept. of Health). There were some indications then that the vaccine was losing its efficacy. But that may not be the full picture.