What is the difference between an antigen test and a PCR test?
What is an Antigen test?
An antigen test is a rapid covid-19 test determining if someone is currently infected with the COVID virus. The FDA approved antigen testing for emergency use in May 2020. The test works by using a sample from the upper respiratory tract (taken with a swab) and adds the sample to a solution that unleashes specific viral proteins. After applying the mixture to a paper strip, you will see if the COVID virus is present. The results are comparable to a pregnancy test (one notification line indicates the test is – negative, two notification lines indicate the test is – positive). While antigen tests are more accessible and faster (results are typically within15 – 30 minutes), they are not as accurate as a PRC test. They are shown only to be 73% accurate. However, an antigen test does lower the chance of spreading the disease.
When an antigen test is positive (meaning they have a high viral load), the individual will need to have a PCR COVID-19 test to determine if the results are accurate.
Although an antigen test is not as accurate as other tests, it can be helpful in certain situations.
- If you visit a high-risk relative, you can do an antigen test to determine if it will be safe for you to visit. It’s important to note that these tests aren’t always accurate, but they lower the chance of spreading the disease.
- Certain places are allowing people to enter who are not vaccinated but have a negative antigen test. For example, many wedding halls are allowing antigen test results instead of a green pass.
- Some workplaces are considering making this a mandatory test when coming into work.
What is an antibody/serology (antibody) test?
When someone becomes infected with a disease, their body produces antibodies to provide the body with protection and immunity against another possible infection. Antibodies can be found in the blood of people who have been infected by a virus or those who have been vaccinated to determine if they have immunity (The immunity may be long term or short term, depending on the virus). Antibodies usually start developing between 1-3 weeks after being infected or vaccinated and indicate if an individual is immune to a virus.
The main difference between an antigen test and a serology (antibody) test is that an antigen test tests if you currently have COVID. In contrast, a serology (antibody) test determines whether you have immunity to COVID through vaccination or recovered from COVID.
EMA Care can provide people entering Israel with referrals to local labs for serology (antibody) testing. We can also provide a concierge serological test at your home or hotel. This service includes assistance tracking MOH submission and obtaining quarantine exemption (exemptions are dependent on serology (antibody) results).
For more information on this service – click here!