Can herd immunity prevent COVID-19?

What is herd immunity and could it help prevent COVID-19?

Herd immunity happens when so many people in a community become immune to an infectious disease that it stops the disease from spreading. Immunity can occur naturally or through vaccination. Natural immunity occurs when many people contract a disease, and in time, build up an immune response to it.

Vaccines that have produced herd immunity include smallpox, polio, and measles. However, there is no vaccine yet for COVID-19 and natural herd immunity to the virus is unlikely, according to Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

People who survive COVID-19 are likely to become immune, according to Dr. Fauci. But there will not be enough of that population to prevent community spread. Herd immunity is only gained when a “significant” portion of the community is immune to a disease, either through contracting it naturally or through vaccines.

For some diseases, herd immunity can have an effect when 40 percent of the population becomes immune to the dis-ease, such as through vaccination, according to The History of Vaccines, produced by the College of Physicians of Philadelphia. But in most cases, 80 to 95 percent of the population must be immune to the disease to stop its spread. This percentage is called the herd immunity threshold.

According to Healthline, a US-based health information service comprised of physicians, nurses, and public health experts, herd immunity is not the answer to stopping the spread of COVID-19 for these additional reasons:

• The research for antivirals and other medications to treat COVID-19 is ongoing.
• Scientists do not know if a person can develop COVID-19 more than once.
• People who contract the virus can experience serious side effects that can lead to death.
• Doctors do not yet know why some people develop severe COVID-19 and others do not.
• Vulnerable individuals, such as older adults and people with some chronic health conditions, could get very sick if exposed to this virus.
• Otherwise healthy and younger people may become very ill with COVID-19.
• Hospitals and healthcare systems may be overburdened if many people develop COVID-19 at the same time.

Currently, medical experts insist that social distancing and frequent hand-washing are the only ways to prevent the spread of SARS-CoV-2, the virus that causes COVID-19.