Rapid At-Home COVID-19 Antibody Tests May Benefit Immunocompromised People

An illustration of a red COVID virus particle surrounded by light blue monoclonal antibodies on a navy blue background.

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Key Takeaways

  • A rapid at-home test for COVID-19 antibodies can help people check their level of protection against the virus.
  • However, health authorities do not recommend using antibody tests to assess COVID immunity or to determine if vaccination is needed. 
  • Having COVID-19 antibodies doesn't mean that you're immune to reinfection.

A rapid at-home test that detects antibody levels against the COVID-19 virus could be useful in gauging immune status, especially for people who are immunocompromised.

CovAb, one of the antibody tests on the market, is authorized by the Food and Drug Administration. Unlike most antibody tests which require blood samples in a lab setting, CovAb only needs a small sample of saliva and produces results in 15 minutes.

How Accurate Is CovAb?

After 15 days of a COVID-19 infection, the rate of getting an accurate positive result (which means that you do have antibodies) is 97.6%.

Jerome Adams, MD, director of the Health Equity Initiatives at Purdue University and a consultant at CovAb, told Verywell that this antibody test can tell people if they have been previously infected and whether they have sufficient immunity from vaccination.

“For immunocompromised individuals who are at an increased risk of contracting COVID-19, it is important they assess their level of protection on a frequent basis," Adams said.

Adams said he uses an antibody test each month to check his own levels because his wife is immunocompromised. As someone who works in a hospital setting, Adams faces a greater risk of being exposed to the virus—another reason he feels the testing is important.

However, health authorities do not recommend relying on antibody tests to determine one's COVID-19 risks or vaccination needs. Antibody testing also should not be used in place of antigen or polymerase chain reaction (PCR) testing for current infection, according to the Centers for Disease Control and Prevention.

What Antibody Tests Can—And Cannot—Tell You

Antibody tests do not show whether you are currently infected with COVID. Instead, they show if you have COVID antibodies—either from having been infected before or from vaccination.

These tests are not recommended for assessing whether you need to get vaccinated or boosted. They also won't be able to determine whether you need to quarantine after having close contact with someone who is infected with COVID.

Adams said that everyone’s antibody levels will vary. Each person’s levels depend on the type and length of exposure, an individual’s immune system, and which variant of the virus is circulating.

Gigi Gronvall, PhD, a senior scholar at the Johns Hopkins Center for Health Security, told Verywell that an antibody test “is really just checking to make sure that your vaccine is still effective.”

Gronvall explained that people who have a poor antibody response—or none at all—after vaccination might ask their healthcare provider about being treated with Evusheld, a mixture of monoclonal antibodies. The treatment might be appropriate as a COVID preventive measure in people who are immunocompromised.

However, there is no clear recommendation on what people should do if their antibody levels are too low, she said.

“The antibody test is not going to be some sort of panacea that’s going to give you the ‘yes or no’ answer—that you’re protected or not protected,” Gronvall said. “But I think it’s a good indicator. If I was immunocompromised, I think I would want that information.”

What This Means For You

An antibody test does not show if you are currently infected with COVID-19, but it can show if your body has created a strong defense against the virus.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

1 Source
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  1. Centers for Disease Control and Prevention. Interim Guidelines for COVID-19 Antibody Testing.

By Valerie DeBenedette
Valerie DeBenedette has over 30 years' experience writing about health and medicine. She is the former managing editor of Drug Topics magazine.