What are COVID-19 antibody tests?

COVID-19 antibody testing, also known as serology testing, is a blood test that's done to find out if you've had a past infection with SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19). An antibody test can't determine whether you're currently infected with the COVID-19 virus.

What does a positive COVID-19 antibody test result mean?

A positive test result with the SARS-CoV-2 antibody test indicates that antibodies to SARS-CoV-2 were detected, and the individual has potentially been exposed to COVID-19.

Does an antibody test show if you have COVID-19?

Antibody tests should generally not be used to diagnose current infection. An antibody test may not show if you have a current infection because it can take 1 to 3 weeks after the infection for your body to make antibodies.

What types of COVID-19 tests are available in the US?

Diagnostic tests can show if you have an active COVID-19 infection. Antibody or serology tests look for antibodies in a blood sample to determine if an individual has had a past infection with the virus that causes COVID-19 but cannot be used to diagnose current COVID-19 infection.

What do antibodies do during the COVID-19 pandemic?

Antibodies are proteins that your immune system makes to help fight infection and protect you from getting sick in the future.

COVID-19 antibody testing explained

Are antibodies beneficial during the COVID-19 pandemic?

When reinfections or breakthrough infections happen, having antibodies plays an important role in helping prevent severe illness, hospitalization, and death. For many diseases, including COVID-19, antibodies are expected to decrease or “wane” over time.

How long do COVID-19 antibodies last?

At this time, it is unknown for how long antibodies persist following infection and if the presence of antibodies confers protective immunity.

What is the most accurate diagnostic test to detect COVID-19?

Reverse transcription polymerase chain reaction (RT-PCR)-based diagnostic tests (which detect viral nucleic acids) are considered the gold standard for detecting current SARS-CoV-2 infection.

What are the different types of viral tests?

Viral Test Types

• Laboratory tests can take days to complete and include RT-“PCR” tests and other types of nucleic acid amplification tests (NAATs).
• Rapid Point-of-Care tests can be performed in minutes and can include antigen tests, some NAATs, and other tests.

Why PCR is better than the rapid COVID-19 test?

“PCR tests are more reliable and accurate due to testing the specific genetic material of the virus, eliminating the interference from other viruses,” said Heather Seyko, a Laboratory Services manager for OSF HealthCare.

Can you have COVID-19 and still test negative for antibody test?

A negative test means that you have no COVID-19 antibodies, so you probably were not infected with the COVID-19 virus in the past. Because it takes time for antibodies to develop, false-negative test results can happen if the blood sample is collected too soon after your infection started.

What does it mean if I have no COVID-19 antibodies in my blood?

You may not have COVID-19 antibodies. This could be because you have not had an infection with the virus that causes COVID-19 or have not received a COVID-19 vaccine. Antibody testing is not currently recommended to determine if you are immune to COVID-19 following COVID-19 vaccination.

Will a person with COVID-19 vaccine have a positive antibody test?

A COVID-19 vaccination may also cause a positive antibody test result for some but not all antibody tests. You should not interpret the results of your SARS-CoV-2 antibody test as an indication of a specific level of immunity or protection from SARS-CoV-2 infection.

How long does it take for antibodies to develop after exposure to COVID-19?

It can take days to weeks after an infection for your body to make antibodies.

Can I return to work after having the COVID-19 antibody test?

Antibody test results should not be used to determine if someone can return to work or school.

What is the COVID-19 viral test?

A viral test checks specimens from your nose or your mouth to find out if you are currently infected with the virus that causes COVID-19. Viral tests do not detect antibodies which would suggest a previous infection and they do not measure your level of immunity.

Which COVID-19 tests are more accurate PCR or antigen tests?

PCR tests are more accurate than antigen tests. "PCR tests are the gold standard for detecting SARS-CoV-2," says Dr. Broadhurst. "It is the most accurate testing modality that we have.

What is the difference between a molecular test and rapid antigen tests for COVID-19?

Molecular tests are generally more accurate and mostly processed in a laboratory, which takes longer; antigen tests—or “rapid tests”—are processed pretty much anywhere, including at home, in doctors' offices, or in pharmacies.

How accurate are COVID-19 PCR tests?

PCR tests are very accurate when properly performed by a health care professional, but the rapid test can miss some cases.

What is a PCR test in the context of COVID-19 testing?

A PCR test stands for polymerase chain reaction test. This is a diagnostic test that determines if you are infected by analyzing a sample to see if it contains genetic material from the virus.

Are molecular or rapid COVID-19 tests more accurate?

Molecular tests are generally more accurate and mostly processed in a laboratory, which takes longer; antigen tests—or “rapid tests”—are processed pretty much anywhere, including at home, in doctors' offices, or in pharmacies.

How long does it take for immunity to wane after receiving the COVID-19 vaccine?

A study published by the U.S. Centers for Disease Control and Prevention found that immunity against severe COVID-19 begins to wane four months after receiving a so-called "booster" third dose of the Pfizer or Moderna vaccines.

Can I get reinfected with COVID-19?

Studies suggest that reinfection with SARS-CoV-2 with the same virus variant as the initial infection or reinfection with a different variant are both possible; early reinfection within 90 days of the initial infection can occur.

Do people produce COVID-19 antibodies after infection?

Most people who've recovered from COVID-19 do make antibodies against the virus.

Do I need the COVID-19 vaccine if I still have antibodies?

Yes, the COVID-19 vaccines are recommended, even if you had COVID-19.