If you find yourself, in reporting on the H1N1 vaccine, needing to explain “community immunity,” the National Institute of Allergy and Infectious Diseases offers a clear graphic that says it all. Community (or herd) immunity occurs when enough people have been vaccinated to contain the spread of an infectious disease — often protecting even those who haven’t been vaccinated.
The graphic isn’t embeddable, but here’s what it looks like. (You can — as we did — easily grab a screenshot since it comes from a government site and is therefore in the public domain.)
The image might also be useful for your H1N1 web page.
