Health screening of travellers will move to real time, within a day or an hour before boarding a flight.

Judged at end-2021. The threshold is health screening (a test or health check) carried out within about one day or less before boarding, required routinely by airlines or governments for many flights. TRUE: such screening (e.g. a required test within 1 day of departure, or rapid testing at the airport just before boarding) became routine on major routes or for international travel to major countries. MOSTLY TRUE: it became routine but only on a limited though significant set of routes or countries. MOSTLY FALSE: pre-departure screening became common but mainly with longer windows (e.g. 48–72 hours), or within-a-day screening existed only in pilots or a few cases. FALSE: no pre-flight health screening regime of this kind emerged. A screening window longer than about a day does not meet 'real time'.

Set before the research began.

1. E1 Requirement for Proof of Negative COVID-19 Test or Documentation of Recovery from COVID-19: Required for All Air Passengers Two Years of Age or Older Boarding a Flight from a Foreign Country to the United States U.S. Centers for Disease Control and Prevention (CDC STACKS archive) · 27 January 2022

   “All air passengers 2 years or older with a flight departing to the US from a foreign country at or after 12:01am EST (5:01am GMT) on December 6, 2021, are required show a negative COVID-19 viral test result taken no more than 1 day before travel”

2. E2 REQUIREMENT FOR NEGATIVE PRE-DEPARTURE COVID-19 TEST RESULT OR DOCUMENTATION OF RECOVERY FROM COVID-19 FOR ALL AIRLINE OR OTHER AIRCRAFT PASSENGERS ARRIVING INTO THE UNITED STATES FROM ANY FOREIGN COUNTRY U.S. Centers for Disease Control and Prevention (CDC STACKS archive) · 25 October 2021

   “a viral test no more than 1 calendar day before the flight's depature from a foreign country if not fully vaccinated against COVID-19”

3. E3 New system for international travel GOV.UK (UK Government) · 17 September 2021

   “Testing for unvaccinated passengers from non-red countries will include pre-departure tests, day 2 and day 8 PCR tests.”

4. E4 New Vaccination Status Recommendation For Entry Requirements Mondaq · 2 February 2022

   “A negative PCR test result obtained no more than 72 hours prior to travel, or a negative rapid antigen test obtained no more than 24 hours prior to travel”

E2 shows that from late October 2021 the CDC required unvaccinated air passengers to the US to take a viral test no more than 1 calendar day before departure. E1 shows that for flights departing from December 6, 2021, every air passenger aged 2 or older flying into the US from a foreign country needed a negative test taken no more than 1 day before travel. That meets the within-a-day threshold for all international travel to one major country before end-2021. Other evidence shows pre-departure testing elsewhere, but often with longer windows: E4 allows a 72-hour PCR test or a 24-hour antigen test and is dated 2022, and E3 gives no time window. So the within-a-day regime was routine on a significant but limited set of routes, not across international travel as a whole.