WebMD BlogsWebMD Doctors

Are You Immune to COVID-19 After You've Had It?

illustration man fighting coronavirus
Neha Pathak, MD - Blogs
By Neha Pathak, MDBoard-certified internistApril 8, 2020
From the WebMD Archives

The virus that causes COVID-19 was only discovered a few months ago, so there’s a lot we’re still learning about it. A few stories coming out of China, Japan, and South Korea of people testing positive for the virus after recovery have a lot of people asking if it’s possible to be reinfected with COVID-19. 

Based on data from other viruses and coronavirus strains, we know that people make antibodies 7-10 days after infection and that, depending on the type of virus, these antibodies can fend off reinfection for months to years after recovery (antibodies provide immunity only to the specific strain of coronavirus that a person was infected with). But, again, since COVID-19 is a new virus, we still don’t know how long antibodies will stay in our system after this specific viral infection.

Does being infected with COVID-19 make you immune? 

We will need to do long-term studies in humans to find out if people who recover from COVID-19 are immune and to learn how long that immunity will last. But again, based on what we know about how our bodies respond to other viruses, it is highly likely that the antibodies we make after infection with the COVID-19 virus will provide immunity for a period of time.

Chinese scientists have conducted some early research with rhesus monkeys and found that antibodies after recovery from COVID-19 protected the monkeys from becoming reinfected after another exposure to the virus. After the SARS outbreak, one study showed antibodies lasted for up to 3 years. Studies from Middle East Respiratory Virus (MERS), another infection caused by a coronavirus, have shown that antibodies can be found in the body for about a year.

The level and time period of immunity can also depend on how an individual’s immune system responds, so there is a lot more we still need to learn about immunity after COVID-19 infection.

Can you get reinfected after recovering from COVID-19?

Some reports have started to emerge about people who have recovered from COVID-19, but later tested positive for the virus again.

Several reports from China have described cases of people with mild symptoms continuing to test positive for the virus, even after recovery. A small study of Chinese healthcare workers also described findings where people continued to test positive even after they had recovered. The study found that these individuals no longer had symptoms and that they didn’t go on to infect their family members. Very recently, the Korean Centers for Disease Control also reported dozens of people that tested positive after recovery. 

Two cases outside of China are even more puzzling: people who had seemingly recovered and tested negative, then weeks later, began to have symptoms again and were found to be positive when re-tested.  

According to experts, these scenarios require further study, but are unlikely to reflect reinfection. A positive test after recovery could be detecting left over virus that may still be present but is not causing infection. For those people who became positive after recovery, it may be that the infection was lingering in their bodies at lower levels and then re-emerged. Or it could mean that prior negative test were false negative (the swab may not have captured viral particles during the testing process).

Research will continue to look at this question, but from what we know about our body’s ability to fight of viruses, it is highly unlikely that a person that has recovered from COVID-19 and made antibodies will become reinfected in such a short period of time.


WebMD Blog
© 2020 WebMD, LLC. All rights reserved.
Blog Topics:
About the Author
Neha Pathak, MD

Neha Pathak, MD, is a board-certified internal medicine doctor and part of WebMD's team of medical editors responsible for ensuring the accuracy of health information on the site. Before joining WebMD, Pathak worked as a primary care physician at the Department of Veterans Affairs and was an assistant professor of medicine at Emory University in Atlanta.

More from the WebMD Doctors Blog

View all posts on WebMD Doctors

Latest Blog Posts on WebMD

  • photo of woman eating yogurt in kitchen
    Diet & Nutrition

    15 Best Foods for Gut Health

    It’s no secret that what you eat every day has a direct impact on your digestive system – and that some foods (hello, greasy takeout!) can make your belly feel worse than others. But certain foods have superpowers in the gut ...

  • photo of person wrapped in blanket holding mug
    Multiple Sclerosis

    Getting Covid With MS

    Christmas season is the most wonderful time of the year, right? Well, not for me. On December 19, 2021, I was diagnosed with Covid-19, just four ...

View all blog posts

Important: The opinions expressed in WebMD Blogs are solely those of the User, who may or may not have medical or scientific training. These opinions do not represent the opinions of WebMD. Blogs are not reviewed by a WebMD physician or any member of the WebMD editorial staff for accuracy, balance, objectivity, or any other reason except for compliance with our Terms and Conditions. Some of these opinions may contain information about treatments or uses of drug products that have not been approved by the U.S. Food and Drug Administration. WebMD does not endorse any specific product, service or treatment.

Do not consider WebMD Blogs as medical advice. Never delay or disregard seeking professional medical advice from your doctor or other qualified healthcare provider because of something you have read on WebMD. You should always speak with your doctor before you start, stop, or change any prescribed part of your care plan or treatment. WebMD understands that reading individual, real-life experiences can be a helpful resource, but it is never a substitute for professional medical advice, diagnosis, or treatment from a qualified health care provider. If you think you may have a medical emergency, call your doctor or dial 911 immediately.

Read More