TERRE HAUTE, Ind. (WTHI)- As both vaccinations and case numbers continue to rise, more health experts are talking about the possibility of herd immunity.
According to the Mayo Clinic, herd immunity occurs when a large portion of the community becomes immune to a disease. It can be achieved in two ways.
If enough people have recovered from COVID-19 and developed antibodies it could halt the pandemic.
Herd immunity can be reached when enough people in the population have recovered from a disease and have developed protective antibodies against future infection.
- Reinfection. It’s not clear how long you are protected from getting sick again after recovering from COVID-19. Even if you have antibodies, you could get COVID-19 again.
- Health impact. Experts estimate that in the U.S., 70% of the population — more than 200 million people — would have to recover from COVID-19 to halt the pandemic. This number of infections could lead to serious complications and millions of deaths, especially among older people and those who have existing health conditions. The health care system could quickly become overwhelmed.
Reaching herd immunity for coronavirus has been increasingly difficult due to variants, vaccine hesitancy, and uneven roll-outs.
Herd immunity makes it possible to protect the population from a disease, including those who can't be vaccinated, such as newborns or those who have compromised immune systems.
The U.S. Food and Drug Administration has approved one COVID-19 vaccine and given emergency use authorization to a handful of COVID-19 vaccines.
But reaching herd immunity through vaccination against COVID-19 might be difficult for many reasons. For example:
- Vaccine hesitancy. Some people may object to getting a COVID-19 vaccine because of religious objections, fears about the possible risks or skepticism about the benefits. If the proportion of vaccinated people in a community is below the herd immunity threshold, a contagious disease could continue to spread.
- Protection questions. It’s not clear how long the COVID-19 vaccines will protect you from COVID-19. Further research is needed to see how much the COVID-19 vaccines reduce transmission of the COVID-19 virus. Also, research suggests that COVID-19 vaccines may have lower efficacy against some of the variants of the COVID-19 virus. New variants, which could be more resistant to vaccines, are regularly emerging.
- Uneven vaccine roll-out. The distribution of COVID-19 vaccines has greatly varied among and within countries. If one community achieves a high COVID-19 vaccination rate and surrounding areas don’t, outbreaks can occur if the populations mix.
The director for the Illinois Department of Public Health, Dr. Ngozi Ezike, encourages people to get vaccinated to help achieve herd immunity.
"The best way to protect everyone is not just counting on other people to get vaccinated it's really to get vaccinated yourself" says Dr. Ezike.