Rapid tests play a crucial role in curbing COVID-19 infections
There are lots of investments in innovation in making these tests easier to use, more sensitive, more reliable in terms of results. Instead of at the beginning of the pandemic, having to wait for a few hours to get the results of your PCR test, from September, October or since last summer, you could have the results in 15 minutes to 30 minutes. That's really an improvement.
Testing remains the most underrated tool to help combat COVID-19
The focus on vaccines was maybe more palatable and easier, until we get the full vaccine coverage, it might be a long year, long two years, or long three years maybe, depending on a number of variants that we hit.
The vaccine is great, but we still need to test people. We still need to cure and to treat and have oxygen to try to save lives and to have drugs that work to save lives and identify transmission and the epidemiological trends in each country. It's all connected and goes together.
We need to say that easy-to-use and low-cost tests would get us to normalcy — not only vaccines, but the daily or weekly testing. It would probably be part of our life.
When to use rapid tests
If you have any symptoms of COVID-19, regardless of whether you’ve been vaccinated, you should get tested right away with either a PCR or antigen test.
SARS-CoV-2 can spread very easily, even if you don’t have symptoms. The faster you can determine if you have COVID-19, the sooner you can isolate yourself, which helps prevent transmission to others. Early testing is also critical because new drugs like those from Merck and Pfizer are most effective if given early in the course of infection, soon after symptoms appear.
If you get a negative antigen test but still feel sick, it is possible that you received a false negative test. Isolate yourself away from others and contact your health care provider to discuss your symptoms. If you get a positive test, you should isolate yourself at home and contact your health care provider as soon as possible.
If you don’t have symptoms but have had close contact with someone with COVID-19, what to do depends on your vaccine status. If you’re fully vaccinated, it's recommended that you wait five to seven days after your exposure and then get a PCR or rapid antigen test. If you’re not fully vaccinated, get tested right away. If you don’t develop symptoms, you should still get retested five to seven days after your exposure.
Like many respiratory viruses, it takes several days for SARS-CoV-2 to build up in your body after exposure. During this early phase of infection, the amount of viral protein is relatively low, and a rapid test may not detect your infection. This is why serial testing over multiple days, with at least 24 hours between each test, is recommended for many antigen tests. Rapid antigen tests are most often accurate when a person is infectious, because that is when the highest amount of virus is in the respiratory tract.
Studies have shown that serial antigen testing – typically two to three tests in one week – is on par with a single PCR test. Remember that a test is only a snapshot of your SARS-CoV-2 status at the time of the test. It’s possible, especially with antigen tests, to test negative during the early stages of infection.
Rapid antigen tests are a welcome tool in society’s fight against the COVID-19 pandemic. When used properly and in combination with other tools such as vaccination, mask-wearing and good hygiene, these actions can help limit the spread of SARS-CoV-2.
How rapid antigen tests work
Rapid antigen tests are designed to detect a portion of protein – known as an antigen – of SARS-CoV-2. First, you take a sample from your nose or mouth with a swab, as directed. You mix the sample with liquid that breaks apart the virus. You then apply the liquid to a test strip that has antibodies specific for SARS-CoV-2 painted on it in a thin line. Antibodies are Y-shaped proteins that recognize and bind to foreign substances such as antigens. If the antibodies bind to the virus proteins, or antigens, a colored line appears on the test strip, indicating the presence of SARS-CoV-2.
These tests are convenient because they are easy to use and provide results quickly, typically within about 15 minutes. Another benefit is that antigen tests can be relatively inexpensive. In contrast, PCR tests usually require laboratory equipment and technicians, take 12 hours to several days to get results and cost $100 or more.