CDC says herd immunity key to stopping measles outbreak
Herd immunity or community immunity is defined as "a situation in which a sufficient proportion of a population is immune to an infectious disease (through vaccination and/or prior illness) to make its spread from person to person unlikely,” according to the Centers for Disease Control and Prevention (CDC) definition said. “Even individuals not vaccinated (such as newborns and those with chronic illnesses) are offered some protection because the disease has little opportunity to spread within the community."
A sufficient number of people with vaccinations may prevent the spread of measles, and herd immunity can be interrupted when enough people refuse to receive their vaccinations.
"We see pockets of unvaccinated individuals, usually children, who are then susceptible to infection. Once an infection gets into that group, it's like a spark in tinder," Gary Procop, fellow of the College of American Pathologists, said. "The real danger is that newborn babies or people with compromised immune systems who cannot generate a good antibody response to fight off the disease would suffer because of the decisions of the group who chooses not to get vaccinated.
"If you are vaccinated, you will either not get the disease, or if you do get the disease, it won't be very serious," Procop said.