What is Herd Immunity?

What is herd immunity? graphicHerd Immunity describes a situation when enough of the population is immune to a disease—either through vaccination or previous illnesses—to make its spread within a community unlikely. Herd immunity protects populations that cannot get vaccinated like those with weakened immune systems (for instance, patients undergoing chemotherapy) or babies.

COVID-19 is a new viral illness, so experts do not yet know what percentage of people would need to get vaccinated to achieve herd immunity.  It is estimated that a large portion of the population, such as 80-85 percent, will be need to be protected from the virus that causes COVID-19 to achieve herd immunity. This means that if 80-85 percent of people are vaccinated or otherwise immune, the virus will struggle to pass between people because four out of five people who encounter the disease won’t get sick. This keeps the virus under control and even protects people who cannot be vaccinated.

Dr. Anthony Fauci, the U.S. leading expert in immunology and infectious disease, recently stated that a far higher number of people need to be vaccinated, likely “closer to 85 percent,” which is around 280 million people in the United States.

Without widespread vaccination of the majority of the U.S. population, the country could see persistent infection, death and additional viral mutations that may require changes to the vaccines, as happens yearly with influenza vaccines.

Stop the spread by getting vaccinated when you can, and continue to wear a mask, physically distance, and clean your hands.