COVID-19 antibody tests have the potential to play a critical role in helping our communities move forward. As the COVID-19 pandemic has unfolded, interest has grown in antibody COVID-19 testing as a way to measure how far the infection has spread and to identify individuals who may be immune. A clinical role is also apparent in testing, since there are so many symptoms COVID-19 has and PCR tests can occasionally have false negative results. This is particularly true when swabs are taken more than five days after symptom onset and sensitivity of PCR tests starts to decrease. Antibody tests have many uses for public health decision making, but demand has largely come from curious, individual people.
Many individuals have questions about the COVID-19 antibody test. We’re here to answer your questions, such as “Are you immune to the coronavirus disease after recovering from it?” and “How long do covid antibodies stay in your system?” As we review some of these questions, keep in mind that an antibody test should not replace a vital test to see if you’re currently carrying the COVID-19 virus.
Antibodies are proteins made by a person’s immune system to fight infections like viruses. They are made to help guard your body from future occurrences by those same viruses. Antibodies can take up to one to three weeks to develop in the body following exposure to the COVID-19 infection.
No, an antibody test can not detect the presence of the virus to diagnose COVID-19. Antibody tests can return negative test results, even in infected patients if antibodies have not developed in their system at the time of taking the test. Antibody tests may also show false positive results if antibodies to another coronavirus type are detected, such as SARS or MARS. Because of this, they should not be used to evaluate if you are currently infected or contagious.
Currently, there are many studies underway to better understand the antibody response following infection to COVID-19, levels of antibodies that are needed for protection, and how long these antibodies last. Many people who have been infected with COVID-19 develop antibodies to that specific virus. The levels of these antibodies can vary between higher levels of antibodies (typically those who have severe disease) and lower levels of antibodies (typically those with milder disease or asymptomatic infection).
There are a lot of things a positive COVID-19 test could mean. A positive test result could indicate that you could have antibodies from an infection with the virus that causes COVID-19. However, there is a possibility that a positive result means that you have antibodies from an infection with a virus from the same family of viruses (called coronaviruses). For example, one that causes the common cold.
Antibodies can take two to three weeks to develop after an infection with COVID-19. It’s important that you’re not tested too soon, because the antibodies may not be detected in your body just yet.
The CDC is currently researching how long COVID-19 antibodies might last for production against the virus. The strength and duration of the immune responses to COVID-19 are not completely understood. Right now, available data suggests that it varies by age and the severity of symptoms. According to WHO, most people, immune responses remain robust and protective against reinfection for at least 6-8 months after infection (the longest follow up with strong scientific evidence is currently approximately 8 months).
If you’re interested in receiving a COVID-19 antibodies test, contact your health care provider or your state or local health departments to see if you’re eligible. Antibody testing for COVID-19 may be done if:
Whether or not you’re eligible for testing may depend on the availability of tests in your area and local or state health department guidelines.
People who receive positive results on an antibody test but don’t have symptoms of COVID-19 or have not been around someone who may have COVID-19 are not likely to have a current infection. Continuing with normal activities, including work and errands, but they should still take steps to protect themselves and others.
Yes, you can go to work if you test positive for COVID-19 antibodies. A positive antibody test is presumed to mean a person has been infected with COVID-19 at some point in the past or has received the COVID-19 vaccine. It does not mean they are currently infected. Antibody test results should not be used to determine if someone can return to work. If you are sick with COVID-19 or think you might have COVID-19, stay home, take care of yourself, stay in touch with a doctor, and avoid public transportation.
Results from currently authorized COVID-19 antibody tests should not be used to evaluate a person’s level of immunity or protection after the person received a COVID-19 vaccination. While a positive antibody test result can be used to help identify people who may have had a prior COVID-19 infection, more research is needed in people who have received a COVID-19 vaccination. Currently authorized COIVD-19 antibody tests have not been evaluated to assess the level of protection provided by an immune response to COVID-19 vaccination.
Antibody tests should generally not be used to diagnose a current infection with the virus that causes COVID-19. 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.
The Roche antibodies test will return COVID-19 antibody levels with a range less than o.4 U/mL or more than 2,500 U/mL. In the case where the response is below the instrument’s limit of detection (less than o.4 U/mL), the test could not detect any neutralising antibodies. Positive results are greater than 0.8 U/mL, with the upper bound listed as greater than 2,500U/mL. Those that receive a result of > 2,500U/mL have a neutralising antibody response of at least 2,500 U/mL indicating a very high antibody level. Currently there is no “recommended level” for a COVID antibody range.
In May 2021, WHO released a scientific update stating that most people who have recovered from COVID-19 develop a strong protective immune response. They summarize that within four weeks of infection, 90% to 99% of people who recover from COVID-19 develop detectable neutralizing antibodies. Though given the limited amount of time to observe cases, they conclude that the immune response remains strong for at least 6 to 8 months after infection. Antibody test results should also not be used to group people together in settings such as schools, dormitories, and correctional facilities.
If you have questions about whether an antibody test is right for you or if you want to explore receiving an antibody test, talk with your health care provider or your state and local health departments. Antibody tests and diagnostic tests are available by prescription from a health care provider and may be available at local health care facilities and testing centers. For more information, contact your health care provider or your local or state health department.
Currently, there are two types of diagnostic tests for COVID-19: a nucleic acid amplification test (NAATs) and an antigen test.
Molecular and antigen tests can detect if you have an active coronavirus infection. If you test positive on either type of test, you should follow the CDC’s guidelines to protect yourself and others.
When you are looking for a COVID-19 test, it is important to find a trusted and experienced testing facility to process your results. BioCollections Worldwide has been on the frontline of developing accurate testing for diseases for over 20 years. We began creating our Covid test prior to the pandemic being declared in the United States when we foresaw the possibility of the COVID-19 pandemic becoming widespread.
Due to our feet-on-the-ground approach, our Covid testing response continues to be fast and accurate, with our PCR tests taking as little as 12 hours to turn around. These same-day results for the more accurate PCR test can give you peace of mind and trusted insight into your health status when you need it the most.
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When you are looking for high quality and trusted COVID-19 testing, look no further than BioCollections Worldwide. Our PCR tests do not require an appointment, are available in 12-24 hours, and are $75 per test. Schedule a test now.