The scientific truth about herd immunity

Editor’s note: The following statement was written and released by area health organizations including UNMC, Nebraska Medicine, Children’s Hospital & Medical Center, CHI Health, Memorial Community Hospital and Health System, Boys Town National Research Hospital, Methodist Hospital/Health System, Pottawattamie County Public Health and Saunders Medical Center.

As we enter a crucial stage in the coronavirus pandemic, Nebraska hospitals and public health agencies want you to know the truth about herd immunity. You may have read about this concept as a way to get us through this difficult time. It would be disastrous for our country, our health care systems, and for millions of fellow Americans.

The herd immunity concept assumes that everyone who recovers from COVID-19 is immune from reinfection. That is an assumption that has not been proven. In fact, medical scientists have now reported a number of persons with proven reinfection. With a virus that has existed for less than a year, it is impossible to know whether people can be reinfected on a large scale.

Let’s look at the numbers:

For herd immunity to take hold, you would need a minimum of 60% of the entire population to be infected. Antibody studies tell us that some small pockets of New York City and Mumbai, India, may have reached 50% infection rates, but cities with major outbreaks have had overall infection rates of less than 25%. Based on CDC testing nationally, we estimate 10% of the U.S. population has experienced COVID-19 coronavirus infection. Given the overall number of confirmed deaths, we can estimate that approximately 0.6% of people with COVID-19 will perish as a result. As of this writing, over 220,000 Americans have already died from COVID-19. So, what would happen if 60% of the population were infected rather than 10%? Here are our estimates for what a “herd immunity” experience in the U.S. would look like:

  • 197 million cases
  • 6 million people hospitalized
  • 2 million deaths

This is not a solution. The loss of life would be many times more devastating than what we see now. The economic impact would be ruinous for our state and country. If you see statements that claim otherwise, keep in mind there has not been a single scientifically verified study anywhere in the world that shows unchecked herd immunity as a solution.

What is the solution? As scientists around the world work tirelessly toward a vaccine, we must follow what we know works to stop the spread.

We agree with state leaders who encourage you to avoid the three Cs:

  • Crowded places: Avoid gathering in groups where you cannot maintain a minimum of 6 feet of distance from others.
  • Close contact: Wear a mask whenever you are within 6 feet of people from outside your household. Masks work — scientific data from around the world continues to show this. In areas with mask mandates, the primary driver of COVID-19 cases is people who spent significant time without their masks on in places like bars and restaurants.
  • Confined spaces: Avoid enclosed spaces with poor ventilation. We know how the virus spreads. When people are physically separated from others by 6 feet or more in well-ventilated areas, they are much less likely to become infected.

We do not have to choose between the total shutdown of society and letting the virus run unchecked through the population. We can instead rely on science and a spirit of helping each other by protecting each other and getting through this together.









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5 comments

  1. Chad Sample says:

    UNMC is an institution of higher learning. It baffles me when I see articles like this that state, " Antibody studies tell us…," but there is no citation to direct readers to the studies that are being referred to. If we want people to educate themselves on topics such as this, we need to provide them the information which the author has based their opinion or facts upon.

  2. Laura Fischer says:

    I am a little concerned about the unintended impact of this messaging. The headline in UNMC Today stated, "The scientific truth about herd immunity: Herd immunity is not a solution." You are correct that herd immunity relies heavily on a certain threshold of the population becoming immune to the disease, which in turns breaks the chain of transmission. However, herd immunity is often achieved through vaccinations, not just someone becoming immune after getting it. I believe your messaging for this article is trying to say that herd immunity through the majority of the population getting the virus is not feasible since we are not seeing long term immunity in those who have already been infected. However, with how the story and title reads, I'm worried it's the CONCEPT of herd immunity being questioned and refuted. This could cause an issue with vaccine hesitancy once a safe and effective vaccine is made available if you try to promote herd immunity through vaccination down the road. The CONCEPT of herd immunity in epidemiology is a very real, valid, and proven method. The path towards achieving it can be up for debate given the specifics of each outbreak, but the concept/term should not be debated. You are correct that herd immunity with this particular virus will not be achieved through the majority of the population becoming infected. However, that does not mean that herd immunity is not the solution through a different means (vaccine).

  3. Cathy Gallentine says:

    Thank you for this information. I just wish people would understand mask mandates so that we could somewhat control this virus.

  4. Raj Kumar pathak says:

    Good

Comments are closed.