Herd immunity occurs when enough people in a group are immune to a specific infection that it cannot spread easily from person to person. Vaccination programs have been successful in creating herd ...

Drivers line up at the entrance of Montgomery County's first mass coronavirus test center in Upper Dublin Township on March 20, 2020. (U.S. Air National Guard photo by Senior Airman Wil Acosta) “Herd ...

You might have heard of herd or community immunity, when a vaccinated portion of a population (aka "the herd") provides unvaccinated people with some protection from a contagious disease. Thanks to ...