Herd Immunity

Herd Immunity

Herd Immunity
Transcript

Because most emergency department visits last a lot longer than a standard office visit, it gives emergency physicians an opportunity to talk to patients and families about a lot of different things. And as the amount of information about COVID-19 continues to evolve, so too does the conversation in the general population. One of the more recent popular conversations centers around a phenomenon known as herd immunity. This term is an infectious disease term that refers to the concept that an infectious agent becomes far less threatening to a species because large numbers within that species become immune to the infecting organism. In general, the two ways that our living organism becomes immune are through exposure with infection and through vaccination. In other words, in the context of COVID-19, immunity is acquired through either being infected with a virus and surviving the infection, or being immunized once a vaccine is developed and available to the public. Herd immunity is also affected by what is known as the R0 number, which is a mathematical symbol for what is known as the basic reproduction number.

This number is an indirect measure of infectivity. In other words, the number of individuals that it is believed that a single infected person will subsequently infect themselves. The higher this number, the more easily transmissible the disease and the greater the number of likely infected people will be. And in the context of COVID-19 and herd immunity, the higher this number, the more individuals that are going to be required globally to reach the threshold of herd immunity. For example, measles, one of the most infectious diseases on earth, has an R0 number of 16, suggesting that as many as 90% of the global population would have to become immune either through being infected and surviving or being vaccinated in order for herd immunity to occur. Because the R0 number for COVID-19 is believed to be around 2, it would suggest that approximately 70% of the world’s population would have to be immune in order for herd immunity to occur. Some have suggested that herd immunity is the answer. Even in the absence of a vaccine. This is incorrect because it would require that nearly 70% of the world’s population would have to become immune through infection. Meaning that approximately 6 billion people on earth would have to become infected, of which nearly 2% would die. This staggering number of deaths is the main reason why herd immunity and the absence of vaccines is not acceptable.

Immunologists, epidemiologists, and other clinical experts agree that herd immunity is not the answer unless we can vaccinate individuals against COVID-19, which is why, while we are waiting for the vaccine to developed, we are still going to continue to practice all of the things that we’ve been learning. We’re going to stay indoors, unless we absolutely have to go outside. We’re going to practice social distancing and all of the other practices that we’ve learned over the last several weeks, so that together we can work to flatten the curve and decrease transmission.

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Herd Immunity

Because most emergency department visits last a lot longer than a standard office visit, it gives emergency physicians an opportunity to talk to patients and families about a lot of different things. And as the amount of information about COVID-19 continues to evolve, so too does the conversation in the general population. One of the more recent popular conversations centers around a phenomenon known as herd immunity. This term is an infectious disease term that refers to the concept that an infectious agent becomes far less threatening to a species because large numbers within that species become immune to the infecting organism. In general, the two ways that our living organism becomes immune are through exposure with infection and through vaccination. In other words, in the context of COVID-19, immunity is acquired through either being infected with a virus and surviving the infection, or being immunized once a vaccine is developed and available to the public. Herd immunity is also affected by what is known as the R0 number, which is a mathematical symbol for what is known as the basic reproduction number.

This number is an indirect measure of infectivity. In other words, the number of individuals that it is believed that a single infected person will subsequently infect themselves. The higher this number, the more easily transmissible the disease and the greater the number of likely infected people will be. And in the context of COVID-19 and herd immunity, the higher this number, the more individuals that are going to be required globally to reach the threshold of herd immunity. For example, measles, one of the most infectious diseases on earth, has an R0 number of 16, suggesting that as many as 90% of the global population would have to become immune either through being infected and surviving or being vaccinated in order for herd immunity to occur. Because the R0 number for COVID-19 is believed to be around 2, it would suggest that approximately 70% of the world’s population would have to be immune in order for herd immunity to occur. Some have suggested that herd immunity is the answer. Even in the absence of a vaccine. This is incorrect because it would require that nearly 70% of the world’s population would have to become immune through infection. Meaning that approximately 6 billion people on earth would have to become infected, of which nearly 2% would die. This staggering number of deaths is the main reason why herd immunity and the absence of vaccines is not acceptable.

Immunologists, epidemiologists, and other clinical experts agree that herd immunity is not the answer unless we can vaccinate individuals against COVID-19, which is why, while we are waiting for the vaccine to developed, we are still going to continue to practice all of the things that we’ve been learning. We’re going to stay indoors, unless we absolutely have to go outside. We’re going to practice social distancing and all of the other practices that we’ve learned over the last several weeks, so that together we can work to flatten the curve and decrease transmission.

Scheduled Appointments

We’ve had a multitude of patients come into the emergency department recently thinking or expecting that by coming to the emergency department we will somehow be able to connect them to a specialist because of an appointment that they’ve had that they decided not to keep. The irony is is that they’ve opted not to go to the primary care doctor or the specialist out of fear of COVID-19 (the novel coronavirus) only to come to the emergency department where the risk of exposure or transmission is actually significantly greater.

If you have scheduled appointments that were scheduled long before the COVID-19 pandemic became a problem in the community, talk with your doctor or the office and let them guide you on what the next step is. Many doctor’s offices now are implementing virtual care platforms that will allow you to keep those appointments in the privacy of your own home. Many of them are also constructing mechanisms to limit the number of patients in the waiting room but still honor appointments. For example, you might have a scheduled appointment with a specialist and they may guide you to come to the office and wait in your car until you are called to come to the office because they want to limit the number of patients in the waiting room.

Regardless of the situation, it is not a wise idea to come to the emergency department for care that your specialists have been coordinating and have been managing. It’s in your best interest to call those doctors with whom you have an established relationship and get guidance from them about what the next step should be.

Prescription Medications

We field a lot of calls about a lot of issues in the emergency department and now that the COVID-19 (the novel coronavirus) pandemic is among us and upon us, we find ourselves fielding a lot of questions about medications. Patients with preexisting medical conditions, whether it puts them in a high risk category or not, are calling us because now that they have remained inside, now that they are practicing social distancing, they’re finding it challenging because they look at their pill bottles and their prescriptions are running low. They have prescription refills on file, some do not, but the question is how do I deal with my chronic medications when the prescriptions are running low in the house? Well, here are some simple recommendations.

Number one, you may be able to find someone who is in a lower risk category than yourself and you can ask them to go pick up your prescriptions for you. You may also call the pharmacy to see if they have a mechanism of home pharmacy delivery. Many pharmacies even that did not have this service have now implemented this service during this pandemic experience. You can also talk with your primary care physician to make sure that you have authorized refills so that you don’t have to go to places to get a prescription filled.

Patients who have medications that are controlled substances that require a physician’s handwritten prescription – it’s important for you to communicate with your doctor so that they can make arrangements in the safest way possible to get you the prescription that you need. In the end, you need to continue to take those medications because they were prescribed for you for a reason. It is not a wise idea to ration your prescriptions. For example, if you’re taking a prescription as prescribed every day and now that you’re running low, you have decided to take the medication every other day or every third day, you run the risk of complications that could make your chronic condition even worse.

Instead, your best bet is to follow up with your primary care physician by telephone or virtual care experience and get guidance from there. If you come to the emergency department, again you will be waiting in a long line of patients waiting to be seen, often only to be told that we cannot refill your prescription. But now having exposed yourself to a multitude of patients who are potentially sick, some of which may in fact be infected with COVID-19. Instead, use your primary care resources and let them help guide you on what the right next step is.

Prognosis Curve

What does it mean to flatten the COVID-19 (the novel coronavirus) curve? Earlier this week I began to see the hashtag #flattenthecurve, so I began to ask people and patients and families what they thought that hashtag meant. The number of answers I got made it clear that we need to have a better understanding of this concept. So in order to understand the concept of flattening the curve, we probably first need to talk about what the curve actually is.

The curve represents a graph that plots the total number of COVID-19 cases in a given city or state or country over time. If you recall from middle school math class, the X or horizontal axis represents time and the Y or vertical axis represents the total number of cases. The plot or curve for COVID-19 like most other viral illnesses has a bell shape, meaning that the number of cases increases over time, then it reaches a peak before finally decreasing. The total number of cases is the height of the curve and the length of time that people are infected is again the horizontal or X axis and both of them are dependent upon the number of infected people and the ease with which the infection is transmitted from person to person.

Flattening the curve simply means decreasing the height of the curve (meaning the total number of cases) and/or decreasing the number of new infections, which means that by controlling the number of new infections, we can decrease the length of time that new infections are identified and decrease the number of people who could potentially transmit the infection to people who are currently healthy. Hand washing, social distancing, self isolation, quarantine of patients with known infections all help to decrease the number of new cases or flatten this curve.

Flattening the curve is the difference between 5 million cases or 500,000 cases. Flattening the curve is the difference between 500,000 deaths and 50,000 deaths, and flattening the curve is the difference between a pandemic that lasts 12 months and one that lasts for only six months. All of us can do our part to help flatten the curve, to decrease the number of infections, and to shorten the length of time that this pandemic affects our communities.

Social Distancing

Let me first start by saying what social distancing absolutely is not. It is not large crowds of patients flooding emergency departments sitting in close proximity to one another while waiting to be seen. Social distancing describes a practice of maintaining a distance of at least six feet between you and someone else in order to significantly limit the risk of either transmitting the virus or becoming infected. In the last week in response to many who either did not understand or consciously chose to not observe social distancing, many state leaders have issued restrictions that make it much harder to not practice social distancing.

Remember, COVID-19 (the novel coronavirus) needs a living host to grow and replicate, meaning that the greater the distance is between infected people and uninfected people, the less likely it is that we’re going to transmit the virus. When we practice social distancing, when we keep ourselves away from others when we feel sick, it limits the ability of the virus to be transmitted to people who do not have it. And when we do those things, we can decrease the number of sick individuals and speed up the time when the number of cases begins to decrease in the community.

PPE

Doctor Profile

Christopher Conti, MD

Emergency Medicine Physician

  • Sports Concussion Physician
  • USAF, Critical Care Air Transport Physician
  • Team Physician, US Soccer Federation

Doctor Profile

Christopher Conti, MD

Emergency Medicine Physician

  • Sports Concussion Physician
  • USAF, Critical Care Air Transport Physician
  • Team Physician, US Soccer Federation

Doctor Profile

Christopher Conti, MD

Emergency Medicine Physician

  • Sports Concussion Physician
  • USAF, Critical Care Air Transport Physician
  • Team Physician, US Soccer Federation

Doctor Profile

Christopher Conti, MD

Emergency Medicine Physician

  • Sports Concussion Physician
  • USAF, Critical Care Air Transport Physician
  • Team Physician, US Soccer Federation

Doctor Profile

Christopher Conti, MD

Emergency Medicine Physician

  • Sports Concussion Physician
  • USAF, Critical Care Air Transport Physician
  • Team Physician, US Soccer Federation

Doctor Profile

Christopher Conti, MD

Emergency Medicine Physician

  • Sports Concussion Physician
  • USAF, Critical Care Air Transport Physician
  • Team Physician, US Soccer Federation

Doctor Profile

Thomas Robey, MD, PhD, FACEP

Emergency Physician

  • Emergency Physician at North Sound Emergency Medicine PC
  • Clinical Research Oversight Committees Chair at Providence St. Joseph Health
  • Assistant Clinical Professor at Washington State University

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