Travel to US - PCR or lateral flow?

Question

With the US reopening to international travelers, if traveling from the UK is a negative lateral flow test recorded with the NHS sufficient for travel, or is a PCR negative test required?

Answer 1

Unfortunately, the NHS explicitly specifies that you cannot use any NHS test for travel purposes.

The CDC FAQ is helpful with basics about testing requirements for entry to the US:

You must be tested with a viral test that could be either an antigen test or a nucleic acid amplification test (NAAT). Examples of available NAATs for SARS-CoV-2 include but are not restricted to reverse transcription polymerase chain reaction (RT-PCR), reverse transcription loop-mediated isothermal amplification (RT-LAMP), transcription-mediated amplification (TMA), nicking enzyme amplification reaction (NEAR), and helicase-dependent amplification (HDA).

Based on personal experience traveling during Covid — when it has been most common for more expensive NAAT/PCR tests to be required for many destinations — as quietly noted above, a cheaper antigen test is an option for travel to the US despite the long rambling about NAAT options.

Accordingly, think the best source is the CDC's checklist distributed to airlines rather than their more public FAQ. The airline checklist more precisely notes antigen tests like these are acceptable:

• Rapid antigen test

• Viral antigen test

• Also, could be noted as Antigen Chromatographic Digital Immunoassay§, Antigen Chemiluminescence Immunoassay§, or Antigen Lateral Flow Fluorescence

With the mention of "Lateral Flow" within the acceptable section, it is easy to see how someone could be confused about the requirements, but the bottom of the checklist adds:

§ Not all immunoassays or lateral flow tests are antigen tests. Antibody testing can also be conducted using these methods. If immunoassays or lateral flow tests are listed, check if the test was an antigen test. Antibody tests are not allowed.

Make sure the test you get provides the exact required words with the results. Ask ahead of time, and you should be able to save some quid with a correctly worded antigen test.

Safe travels!