(Photo : Alexas_Fotos from Pixabay)

The presence of antibodies against the Coronavirus Disease 2019 (COVID-19) does not ensure the virus has fully left a person.

According to Dr. Dara Kass, an associate professor of emergency medicine at Columbia University Irving Medical Center, "you can still have [the] virus in your respiratory system but also have antibodies to the virus in your blood."

Playing it safe

Dr. Kass, who is also an emergency room (ER) physician in New York City, tested positive for COVID-19. She stayed in a hotel room after her ER shifts because she "knew that antibodies wasn't perfectly correlated with the ability to not expose my family," Dr. Kass said to Yahoo News.

She was nervous to return home because her son has a compromised immune system due to a liver transplant. Individuals "who have weakened immune systems, or are immunocompromised," are prone to COVID-19, according to infectious disease specialist Alan Taege, MD, of Health Cleveland

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Dr. Kass only moved back home after testing negative for COVID-19. 

Theresa Canning Zast went to the emergency room after feeling symptoms of the flu. Zast told Yahoo News, "It was flu-like, so I actually didn't think it was COVID. I just went to the emergency room as a precaution."

Unfortunately, her tests came back positive. This prompted her to undergo self-isolation for weeks. Thinking her symptoms had already improved, she decided to donate her blood plasma to be used as convalescent therapy.

Zast delayed her donation when she received the results of her blood test on April 7. According to Yahoo News, her immune system "had developed enough antibodies against the virus to qualify for plasma donation, but she would be unable to donate because her nasal swab test had yet again come back positive for the coronavirus."

She finally tested negative for COVID-19 on April 15.

According to the Proceedings of the National Academy of Sciences of the United States of America (PNAS), doctors have been using convalescent plasma (CP) transfusion for more than a century. It has treated infectious diseases in the last two decades, such as Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), and the Influenza A (H1N1) pandemic in 2009.

Immunity not guaranteed

Yahoo News says there are two coronavirus tests: nasal swab and blood test. The first detects an ongoing infection, while the second checks for antibodies, "which provides evidence of past infection." 

A blood test can determine if the person can donate blood plasma for other patients and check if they are cannot be reinfected by COVID-19.

While there is no vaccine or tried-and-tested way of being immune from COVID-19, prevention is the next best thing. This means following WHO's safety guidelines for the pandemic: no touching of eyes, nose, mouth, and face, frequent handwashing, and social distancing.

Undergo self-isolation if suspected to have mild symptoms of COVID-19. Only go to the hospital once the symptoms get worse. 

Citing the Centers for Disease Control and Prevention (CDC), Yahoo News said, "people with COVID-19 can end home isolation at least seven days after symptoms first appeared, provided their symptoms have improved and they have gone without fever (and without fever-suppressing medication) for at least 72 hours."

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