ITHACA, N.Y. (NEWS10) — Herd immunity is when a large portion of a population becomes immune to a particular illness, thus protecting the portion of the population that is not immune. There are two ways herd immunity can be achieved, through infection or vaccines, according to the Mayo Clinic.
In order for a population to achieve herd immunity from COVID-19, approximately 70% would have to have gotten the virus and recovered or received a vaccine. New research from Cornell University suggests public sentiment towards a COVID-19 vaccine might make achieving herd immunity difficult.
Public support for a COVID-19 vaccine is dependent on how effective it is. The minimum effective rate in order to speed up the release of a COVID-19 vaccine is 50%, a figure set by the U.S. Food and Drug Administration (FDA). Less than half of 2,000 Americans surveyed said they would get the vaccine if it only met the minimum effective rate, according to Cornell University.
The number of Americans surveyed who would get the vaccine increased to 61%, based on a 90% effective rate.
Cornell University said public sentiment is also affected by the length of time the vaccine would provide protection and whether or not there are major side effects. A greater percentage of people feel favorable towards getting a vaccine when the protection duration increases from one to five years and when there is a lower chance of side effects.
The survey also indicated people were more likely to support a vaccine if it was backed by an organization like the World Health Organization or the Centers for Disease Control and Prevention (CDC).
Where the vaccine is manufactured also affected public support, dropping slightly if it were made outside of the United States in the United Kingdom and dropping more significantly if it were manufactured in China.
“Even one of the best-case hypothetical vaccines presented – developed in the U.K and approved by the FDA with 90% efficacy, five years of protection, few side effects and CDC endorsement – (the percentage of those who would get a COVID-19 vaccine) barely reached the estimated threshold for herd immunity, with 71% of Americans willing to take it,” Cornell University said.