Herd immunity can theoretically protect us from COVID-19.Infectious disease expert explains

Many have asked one simple question, as the United States has recently surpassed 200,000 deaths from the coronavirus.

With a politician Public health expert Advertised Herd immunity As a way to stop COVID-19 without a vaccine. Scientific concepts explain that if a high proportion of the population becomes infected, develops immunity and survives, the virus will become extinct. Vaccines speed up this process much more safely, but experts believe that it will be 2021 before most Americans are vaccinated.

Most epidemiologists have 50% to 70% of the population Coronavirus Either vaccination or illness ends the pandemic. That’s because when most people are immune to a particular disease, vulnerable people are less likely to encounter carriers of that disease.

But it was done Flock Is immunity a viable way to stop the spread of the virus before the vaccine becomes available?

We spoke with Henry Freimow, an infectious disease specialist at Cooper University Healthcare in Camden, and Michael Ruvasser, a professor of epidemiology at Drexel Donife School of Public Health.

Fraimow: Herd immunity is the concept that many people in a population cannot be infected with a particular infectious agent. infection Previously, there were antibodies or immunity that prevented them from becoming infected, or they were vaccinated against the infection. Infections in the community require people who are susceptible to the disease. The higher the proportion of people who cannot get sick, the less likely it is to be transmitted.

Fraimow: How you achieve it depends on the type of infection. With some infectious diseases, which infect virtually everyone, the virus becomes more difficult to spread. For example, it is known that certain viruses carried by mosquitoes such as Zika fever have attacked the country and infected a large population. After that, those people became immune and it became more and more difficult to find people infected with mosquitoes. Another way to achieve herd immunity is to vaccinate everyone. Vaccination with a high proportion of the population does not allow enough people to spread the infection. In some cases, herd immunity is achieved by a combination of both.

LeVasseur: The fewer people you come in contact with, the less likely you are to get infected.And if less number People who are susceptible to illness are less likely to come across potentially infected people, even if they are not vaccinated.

LeVasseur: In theory it is possible. It depends on the pathogen. With COVID-19, there are many things we still don’t understand. One of the things we have seen is that when people are infected, the antibody response lasts only 3-4 months. This is the same as seen with other coronaviruses. The second issue was confirming reports of people re-infected with COVID-19. The idea of ​​exposing 70% of the population at the same time to obtain herd immunity is such a failure of public health. The number of people dying is staggering. It’s like throwing your baby in the bath water, setting it on fire, and doing it on a truck.

Fraimow: Many of these numbers come from what is called the reproductive count of the virus. This shows how many people will spread the virus if no one is infected with the virus. For COVID-19, the number varies from 2 1/2 to 3. These numbers are influenced by people’s social distance and so on. To achieve herd immunity, so that when the average person enters many people, so many people are immunized that the infected person spreads the virus to less than one other person. There must be sufficient immunity of the person. As such, the number of infected people continues to decline.

LeVasseur: It’s like when you have a burning building and you’ll need a lot of water to put it out. Instead, say, “Burning the next building and the next building.” You don’t want to do it with an infectious disease. It’s not ethical. It does not reduce costs. There is nothing about a meaningful approach.

Fraimow: There are several reasons why it’s not a good strategy. Young people have a lower risk of serious illness than older people and people with immunodeficiency, but there are still people in the group who die of severe illness. We are not good at distinguishing between those who are not at risk and those who are at risk.For example, many illnesses College student, Most people are ok Virus, We need to consider that they all have family and contacts. Some of them are infected and can infect others at risk. Another problem is that we do not fully understand what the duration of immunity is. All of this raises some concerns about how this concept of herd immunity works.

If you intend to rely on natural infections to result in outbreaks, the proportion of infected and immunized populations is much lower than the number required to achieve a herd, even in areas of high infection rates. In the process of exposing many people to infection, we carry out the methods we have been doing. This is an overwhelming medical system for sick people.

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