What is herd immunity?
Herd immunity occurs when a large group develops immunity to a specific disease. When a significant number of people become immune to a disease, the root of the disease — either a virus or bacteria — can no longer survive and spread. Herd immunity is achieved when most of a population reaches immunity, meaning certain individuals may still be vulnerable to disease.
Who benefits the most from herd immunity?
Individuals who are most vulnerable to diseases benefit the most from herd immunity. These are typically people with compromised immune systems, babies, and the elderly.
How can we achieve herd immunity?
More contagious viruses require a larger percentage of the population to be vaccinated before herd immunity sets in, meaning the most efficient way to achieve herd immunity is by vaccinating. Currently, the U.S. administers approximately 1.7 million COVID-19 vaccines daily.
Experts predict that we may reach herd immunity when about 70% of the population is vaccinated. Vaccines are so effective because they build resistance. By tricking your body into thinking it is infected, vaccines trigger your immune system to produce protective antibodies.
Getting your COVID-19 vaccine means that the next time you come in contact with the novel coronavirus, your army of antibodies is prepared to ward it off. Herd immunity by vaccines is what ended the U.S. polio pandemic.
What obstacles are we facing heading towards herd immunity to COVID-19?
Not everyone will elect to be vaccinated. Some individuals may develop immunity via repeated exposure to the virus, but medical experts strongly recommend against this, noting that natural herd immunity rarely occurs this way.
A big obstacle we face is that the virus is "novel," or new. This novel coronavirus has never infected humans before. Without existing immunity to build upon, everyone is vulnerable to infection.
With the vaccines also being new, we lack the data needed to predict how long their immune protection effects will last.
Where can you get a COVID-19 vaccine?
Eligible people can receive their vaccines now at one of our vaccination sites:
Request yours and learn more at our COVID-19 Vaccine Hub.
NYT | Why Vaccines Alone Will Not End the Pandemic
NYT | When Could the United States Reach Herd Immunity? It’s Complicated.