Many people hope that COVID-19 immunity can bring them back to "normal life" and that those who recovered from COVID-19 do not need to be concerned about being infected or infecting others.
Unfortunately, there are too many unknowns about COVID-19 immunity to be sure.
Learn what we currently know about developing immunity to COVID-19 after an infection, what herd immunity is and what antibody testing can tell you.
Can You Get Coronavirus Twice?
There is currently no conclusive evidence that points to how long coronavirus immunity lasts. According to the Centers for Disease Control and Prevention (CDC), there have been recorded cases of coronavirus reinfection.
Scientists continue to study the duration of coronavirus immunity and how likely a person is to get COVID-19 twice. Because of these unknowns, the CDC recommends always adhering to coronavirus prevention measures, including vaccination and masking, even if you've been infected before.
How Viruses Work
To understand coronavirus immunity, it is important to know how viruses work and how the immune system responds to them.
Viruses are pieces of genetic material surrounded by a protein coating. They can't reproduce without finding "host cells." This is why they seek out cells like the ones in our bodies.
When viruses enter our bodies, they find a cell and inject it with their genetic material. This allows them to take control of the cell and multiply.
To battle this, the body's immune system must destroy infected cells. When the body first encounters a new viral infection, it deploys T cells, which find and kill infected cells. If the infection continues, the body then deploys B cells, which create antibodies that can better attack infected cells.
Even after the infection has passed, antibodies remain in the body to help the body fight off future infection. How long these antibodies last in the body varies, ranging from days to a lifetime.
Understanding COVID-19 Immunity
There are still many unknowns when it comes to coronavirus immunity. At this time, there is currently no way to know how long any immunity could last.
Other types of coronaviruses, such as MERS, do induce immunity, often for several years. Many hope that SARS-CoV-2 will behave similarly.
Unfortunately, the data is not cut-and-dry. Most studies of immunity to coronaviruses, including SARS-CoV-2, focus on people who had severe disease and were hospitalized for their condition. There is significantly less data on the immune response in people who had mild symptoms or were asymptomatic.
All of these unknowns are why the Centers for Disease Control and Prevention and the World Health Organization currently state that there is no evidence to suggest novel coronavirus infection imparts immunity. More research needs to done.
Coronavirus Herd Immunity
Herd immunity is when most of a population is immune to an infectious disease, thus providing indirect protection to people who aren't immune to the disease.
Vaccines are the best tactic for creating herd immunity. Even if the majority of the population has had an infectious disease and/or vaccinated, the disease can still be transmitted among children who haven't yet been exposed to the virus and people who are immunocompromised.
Coronavirus Antibody Tests
Coronavirus antibody tests identify specific antibodies in a person's blood that indicate they have been infected with the virus. Antibody tests are different than the tests used to detect an active coronavirus infection.
Antibody Tests and Coronavirus Immunity
Antibody tests do not tell you whether you are immune to coronavirus. They simply indicate if you have or haven't been infected with the virus. If you have been infected, it doesn't necessarily mean you are immune.
A positive antibody test isn't an "immunity passport." It does not mean that you can stop practicing the prevention measures that keep you and others safe, such as:
What a Coronavirus Antibody Test Can Tell You
If a coronavirus antibody test can't tell you if you're immune to the virus, then what can it tell you?
Antibody tests give you a better understanding of how you have personally been infected with the virus.
Antibody tests are also being used to help determine how widespread coronavirus infection is in certain communities. This can be beneficial for creating public policy and better understanding how to keep communities safe.
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