The Path to Herd Immunity

Over the last month, vaccines tasked with arming us against COVID-19 have begun arriving around the country, bringing with it much excitement that we might soon be rid of the global pandemic that has plagued us. While it may be a while before the public-at-large is able to receive the vaccine, the topic is hot among dinner tables and water cooler conversations.

One popular term making its way around these discussions and onto the news is ‘herd immunity.’  Also known as ‘population immunity,’ herd immunity occurs when a large percentage of a community becomes immune to a disease, inhibiting its ability to spread to the point where the whole community, even those within it who are not immune, are protected from the disease. This is especially beneficial in cases where a community consists of people who are at increased risk from a disease, such as newborns and the immunocompromised.

It is easy to see why ‘herd immunity’ is an exciting prospect. After almost a year of restrictions and precautions, we are all ready for things to get back to normal, but it won’t be an easy path.

“For herd immunity to occur a large percentage of the community’s population needs to be immune, either through vaccination or previous infection,” explains Dr. Gregory Stepp of the White-Wilson Family Medicine Clinic. “This percentage varies by disease with the more contagious diseases having a higher percentage to meet.  For example, measles, a highly contagious disease, requires approximately 94% of a population to be immune for herd immunity to occur. It is a tall order, but as we have seen in the case of measles, polio, mumps and chickenpox, it is possible through vaccination programs.”

Because the virus that causes COVID-19 was previously unheard of and scientists continue to learn about it, the threshold for herd immunity (HIT) that needs to be met is unknown at this time. Many experts anticipate that number to fall somewhere between 50% and 90%, meaning the majority of people in a community will need to be immunized against the virus for herd immunity to be achieved.

“If we all get on board, this is doable,” says Dr. Stepp, “especially with the vaccine becoming available.”

The availability of a vaccine often makes a huge difference when it comes to achieving herd immunity.  Without a vaccine, we would have to rely on a large number of the population becoming sick with and recover from COVID-19. Depending on the disease, that can be extremely risky.

“It is very clear to us that COVID-19 can cause severe illness and even death in certain instances,” Dr. Stepp elaborates. “Waiting to meet the HIT through natural infections will result in more suffering and death than is necessary, not to mention, the increased strain it will put on our already overstressed health care system. Vaccines are a way to circumvent these issues.”

There is also the hurdle of vaccine hesitancy. As is the case of any vaccination, some segment of the population will be opposed to it, whether it’s for ethical or religious reasons or because people are uncomfortable with the speed at which this vaccine was developed. According to Pew Research Center, approximately 60% of the U.S. population reports that they will or probably will receive a COVID-19 vaccination once it becomes available. And while this does fall within the range of the estimate HIT, it leaves little room for error.

“I understand that the idea of a vaccine can be scary, especially one that has been created so quickly,” says Dr. Stepp. “However, it is important to know that everything the research tells us is that this vaccine is safe. While getting control over the virus is the ultimate goal, safety is and has always been at the forefront of the discussion. We have proof of this. Millions of people around the country have received the vaccine and of those million and very few instances of severe side effects have been reported. “

“There is a lot of misinformation out there and it can be hard to know what is correct,” he continues. “But don’t just take my word for it. Ask your doctor and the medical professionals in your life. Get multiple opinions from people who know the science and not just your peer group. That way you are making the most informed decision one way or another.”

“Herd immunity would be an excellent way to fight back against COVID-19,” Dr. Stepp explains, “but there is still the chance that it may not happen. That is why it is important to continue taking precautions like the ones we have been. This disease is still very new to everyone and while we know more than we did in March, there is much yet to learn. As scientists and doctors continue to do their part, I urge you to continue to do yours as a show of support.”

Dr. Gregory Stepp is a board-certified family medicine practitioner at White-Wilson Medical Center in Fort Walton Beach. Click here to learn more about Dr. Stepp and his approach to patient care.

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