Serology tests do not clear individuals who may have been exposed to COVID-19


(CDC) – As COVID-19 is a new and rapidly evolving virus, significant updates are provided as available.

The U.S. Centers for Disease Control and Prevention (CDC) has offered the following guidance for COVID-19 antibody testing.

Confirming COVID-19 infection is generally done through Polymerase Chain Reaction (PCR) testing using various platforms. CDC has also developed a laboratory test to help estimate how many people in the United States have been infected with SARS-CoV-2, the virus that causes COVID-19. This test is referred to as a serology test or antibody test. The CDC will develop guidance for the use of antibody tests in clinical and public health settings.

An antibody test looks for the presence of antibodies, which are specific proteins made in response to infections. An antibody test is typically performed on a blood sample. Antibodies are detected in the blood of people who are tested after infection; they show an immune response to the infection. Antibody test results are especially important for detecting previous infections in people who had few or no symptoms.

An antibody test may not show if you have a current COVID-19 infection because it can take 1–3 weeks after infection for your body to make antibodies. To see if you are currently infected, you need a viral test. The viral tests identify the virus in samples from your respiratory system, such as a swab from the inside of your nose.

It is not known if the antibodies that result from SARS-CoV-2 infection will provide someone with protection (immunity) from getting infected again. If antibodies do provide immunity, it is not known how much antibody is protective or how long protection might last. CDC scientists are currently conducting studies to answer these questions.

CDC’s serologic test has been designed and validated for surveillance and research purposes. It is designed to estimate the percentage of the U.S. population previously infected with the virus – information needed to guide the response to the pandemic and protect the public’s health.

The CDC test is not currently designed to test individuals who want to know if they have been previously infected with SARS-CoV-2.

As more information becomes available through CDC, updates will be offered accordingly.

At the present time, antibody testing is reserved for surveillance and research purposes only, and is not indicated for “clearing” individuals who may have been exposed COVID-19.

DPHSS is planning to conduct a Special Populations Seroprevalence Survey (among contacts of positive COVID-19 cases) and a Community Level Seroprevalence Survey (a random survey of Guam’s population) in the future:

For inquiries on COVID-19, contact 311 through a local number, or call the Joint Information Center at (671) 478-0208/09/10.