Herd immunity takes place when a substantial percentage of a community achieves protection from a particular disease. This mass immunity reduces the ability of disseminating the disease to and from individuals. Consequently, the entire community (this is where the word ‘herd’ comes into play), is now shielded vs. only those who are actually immune.
According to the Mayo Clinic, “a percentage of the population must be capable of getting a disease in order for it to spread. This is called a threshold proportion. If the proportion of the population that is immune to the disease is greater than this threshold, the spread of the disease will decline. This is known as the herd immunity threshold.”
The more transmittable the disease, the larger percentage of the community needs to become immune to the disease in order to put an end to the spread.
Herd immunity has the ability to protect the community from a disease, which includes those who cannot or will not receive a vaccine, including infants and people who have a compromised immune system.
How does a community attain Herd immunity?
Vaccines and infection are the two primary routes to eradicating the COVID-19 virus through Herd immunity.
1. Original infection
One pathway to Herd immunity is when a substantial portion of the population recuperates from a disease, and then subsequently creates antibodies that protects from future infection.
But the truth is that there are some serious challenges when it comes to creating Herd immunity. For starters, reinfection is possible with COVID-19; scientists are not certain how long the antibodies last for, or when someone could possibly get infected again. Secondly, it is estimated that at least 70% of the United States’ population would need to bounce back from the virus. To put some context to these numbers — we’re talking 200 million people. This staggering ratio has the possibility of infections ending up with extraordinary complications, and millions of people dying.
Another route to achieve Herd immunity is through vaccinations, which have the ability to develop antibody protection against infection. With the exception of short-term side effects, vaccines have the potential to produce immunity without causing serious illness or death. Some examples of Herd immunity via vaccines that have effectively limited contagious diseases include polio, diphtheria, and smallpox.
There are some hurdles to achieving COVID-19 Herd immunity due to mass vaccination, including those who simply do not want to receive a vaccine. Their reasons may range from skepticism, to religious obligations. Another challenge is the infancy of these vaccines and not fully understanding how long they provide protection from the virus, or if it covers new variants. And finally, yet another potential roadblock includes an inconsistent dissemination of the vaccine; it varies from country to country.
What is the forecast for the U.S. to achieve Herd immunity?
As the amount of fully vaccinated people grows, the United States is making headway in the direction of reaching Herd immunity. Additionally, as of this blog publication, over 30 million individuals have been infected with COVID-19 and carry antibodies (although the total duration of protection is unconfirmed).
The U.S. Food and Drug Administration authorized COVID-19 vaccines that have incredible efficacy against against extreme illness or even death. Although it may be impossible to terminate the COVID-19 virus completely, at least people who have been vaccinated are much more likely to live with the virus.
On the other hand, as mentioned above, some experts believe that achieving a Herd immunity threshold is appearing unlikely due to a variety of reasons, including resistance to getting the vaccine, new variants emerging, and a hold-up of providing vaccinations for all children.
Due to this reality, it is not certain if or when the U.S. will conquer herd immunity.
Be sure to catch our upcoming Auxo Medical blog post — we will discuss racial disparities as it relates to COVID-19 outcomes and treatment.