As testing for COVID-19 has become a regular part of everyday life, especially when it comes to traveling, making sure you get the correct test is of the utmost importance.
When faced with the need to get a COVID-19 test, it’s important to know that not every test is created equal, with different levels of accuracy as well as the time it takes to get results back. Some countries will only accept RT-PCR tests — considered the most accurate — while others will accept proof in any form of negative test to enter. All viral tests detect a current infection and are most accurate when “the person is tested when viral load is generally highest,” the CDC explains.
Many states and countries mandate travelers get tested before and after a trip, while some places require testing to attend things like sports games or a concert. And while the Centers for Disease Control and Prevention does not require vaccinated Americans to get tested before or after domestic travel, the agency does require all international travelers to get tested within three days of boarding a flight to the U.S.
Below, we break down each type of test, according to the CDC, explaining the benefits of each, so travelers know everything they need to before their next trip.
This is the gold standard of COVID-19 tests, with the most accurate results available. A RT-PCR test (or reverse transcription polymerase chain reaction) uses Nucleic Acid Amplification Tests (NAAT) to detect genetic material. NAAT’s can be performed with a nose swab — with something that looks like a long Q-tip — or with saliva.
“The NAAT procedure works by first amplifying – or making many copies of – the virus’s genetic material that is present in a person’s specimen,” according to the CDC. “Amplifying or increasing the copies of nucleic acids enables NAATs to detect very small amounts of SARS-CoV-2 RNA in a specimen, making these tests highly sensitive for diagnosing COVID-19.”
The sample is often sent to a lab and results typically take a few days, but can vary.
This test also uses NAAT, but is run “at or near the place where the specimen is collected,” providing quicker results, according to the CDC.
These are at-home or point-of-care tests that provide results typically within about 15 minutes, according to the CDC. However, they are less sensitive than RT-PCR tests. These tests are often performed with a nose swab, which is then placed directly into an extraction buffer or reagent.
Additionally, while the CDC requires all international travelers to get a test within three days of boarding a flight to the U.S., rapid viral tests are acceptable.
Rapid tests can be taken and viewed at home, like with the Ellume COVID-19 Home Test, while several airlines offer passengers both at-home and in-person testing options at airports.
Antibody tests are unique from viral tests in that they do not detect a current infection. Rather, these tests, also known as serology tests, look for antibodies that may have formed in a patient’s blood due to a previous infection, according to the CDC.
When someone contracts COVID-19, their body works to fight off the virus, creating antibodies. Typically, it can take one to three weeks after an infection for a body to make antibodies.
The tests are typically performed with a finger stick or blood draw, according to the FDA.
Many countries require negative viral tests or proof of vaccination to enter, but some allow travelers to substitute that for proof they contracted COVID-19 and recovered. Greece, for example, plans to welcome tourists this summer and will accept proof of antibodies to enter. Similarly, Croatia allows visitors to present proof of having recovered from the virus in place of a COVID-19 test.
Alison Fox is a contributing writer for Travel + Leisure. When she’s not in New York City, she likes to spend her time at the beach or exploring new destinations and hopes to visit every country in the world. Follow her adventures on Instagram.