In most cases of a viral infection, if an individual is infected with a particular virus, that person develops an immunity to it. In other words, typically a person infected with a specific virus develops a defense mechanism to it. That individual is able to stave off a future infection by the same virus because of this acquired immunity. Many infectious disease experts, medical professionals, governmental officials, and members of the general public are in unison in their hope that when an individual is infected with COVID-19, that person does develop some level of immunity going forward into the future. 

The Status of Research Regarding COVID-19 Infections and Immunity to the Virus

Since infections from the novel coronavirus now known as COVID-19 were declared a pandemic, there has been a considerable level of confusion and conflicting information about different aspects of the virus. This arises primarily from the fact that COVID-19 is a novel virus. Novel means that this is the first time that this strain of coronavirus has infected human beings. The stark reality is that everyone from infectious disease specialists to frontline healthcare workers to government officials to the general public are learning about COVID-19 as the pandemic spreads – and all of these categories of people essentially are discovering more facts about COVID-19 as the disease progresses.

A Closer Look at What Is Meant by Immunity

In basic terms, immunity is the body’s ability to fight off dangerous pathogens like COVID-19. In many cases, when an individual is infected with a virus, the body produces antibodies to that particular virus. Because antibodies are created, in this type of situation the body creates immunity and staves off future infection.

What we are coming to understand during the COVID-19 pandemic is that immunity is not an all or nothing proposition. Immunity is something of a spectrum. 

There are instances in which a virus can cause a long term, even permanent, immunity to that virus. Chickenpox typically is an example of this type of situation.

There are other viruses that provide immunity for a period of time, sometimes for a matter of a few years. Over time, the extent of the immunity begins to fade.

It is also possible that certain viruses don’t cause an immune response. Thus, in theory, a person can become re-infected by that virus at a future time. As will be discussed in a moment, certain coronaviruses that cause the common cold do not cause an immune response. People can get reinfected time and again with one of four different coronaviruses that cause the common cold. 

COVID-19 Versus Other Coronaviruses: An Immunity Comparison

COVID-19 is a novel coronavirus. There are at least six other coronaviruses that we’ve dealt with in the past, some we continue to deal with today. 

SARS is a dangerous coronavirus. There are people who had SARS in 2003 and 2004 that do have antibodies today to stave off reinfection.

MERS is another dangerous coronavirus, perhaps the most dangerous of all coronaviruses. The death rate associated with MERS is about 35 percent, far higher than that associated with SARS and COVID-19. Survivors of MERS did develop an immune response that was present after two years. There is no good data on MERS reinfection because the death rate is so high and because there has been only an extremely small number of MERS infections around the world in the past eight years. There have been 2,500 cases of MERS infection during the past eight years, just over 310 a year internationally. 

Every year, people around the world deal with the common cold. There are four different types of coronavirus that are the causes of upwards to 30 percent of all common colds experienced by people in the United States and elsewhere around the world. These four types of coronavirus are far, far less serious than COVID-19, SARS, and MERS. There appears to be no meaningful immunity to these four types of coronavirus. 

Immunity From COVID-19: The Bottom Line

Research is ongoing regarding immunity following a COVID-19 infection. At the present time, there is some data to suggest that some people do develop an immune response following a COVID-19 infection. With that said, there are also cases in which people who’ve had a COVID-19 infection appear to have experienced reinfection. If that has occurred, that is indicative of a lack of an immune response, at least as far as these particular individuals are concerned. 

As more people survive a COVID-19 infection, and as more time is paced between these infections, we all will have a clearer picture of the immunity issue following an infection by this novel coronavirus. In addition, research intensely underway to develop a reliable vaccine to truly protect people from infection by the COVID-19 virus. There is some consensus that a vaccine will be available to the general public in the spring of 2021.