According to a CDC request, airlines must comply with these rules to receive permission to disembark passengers in the United States.
What kind of tests are needed?
The CDC stipulates that negative results must come out of a test that can detect an ongoing infection, taking pieces of the pathogen itself. Two types of tests fall into this category: molecular tests (which include PCR tests) and antigen tests. (Antibody tests, which can only determine whether someone has been infected in the past, do not count.)
Molecular tests look for segments of the virus’s genetic material, or RNA. The most common molecular tests are based on a tried and tested technique called polymerase chain reaction, or PCR – a gold standard in the diagnosis of infectious diseases. PCR tests can be expensive, and since they require samples to be sent to laboratories, it may take a few days to return the results. Experts say it is a good idea to plan ahead if you choose this type of test.
There are some quick molecular tests that can be performed from start to finish in a doctor’s office in minutes. This includes Abbott’s ID Now test. They are considered less accurate than PCR-based tests, but will provide answers more quickly.
Antigen tests look for portions of coronavirus proteins, or antigens. They tend to be less accurate than molecular tests and are worse at finding the virus when it is scarce. But most antigen tests can be done very quickly and cheaply, taking just a few minutes to deliver the results.
Certain antigen tests are only released for use by people with symptoms and can provide inaccurate results more often when used to screen people who feel healthy.
Depending on the traveler’s country of origin, some tests may not be available – and as a result, these new rules are likely to make it much more difficult for people to enter the United States. Tests are generally offered by health care providers or community test sites, which can be located at local travel agencies and health providers. Some airports, such as Heathrow in London, are offering coronavirus testing on site. And some airlines, such as American, Jet Blue and United, are offering to help their customers in certain countries organize tests. Delta, for example, has partnered with the Mayo Clinic and national health officials in several countries to facilitate the testing and travel process.