Local COVID travel advisories could be returning

Chicago added three states and a U.S. territory to its COVID-19 travel advisory Tuesday.

The big picture: State and local-level travel rules were a blunt-force approach to slowing the pandemic last year — and ones that often proved difficult to actually enforce.

• But with vaccination rates in many states stalling and concern about the more contagious Delta variant growing, it's possible that they may return.

Driving the news: Unvaccinated travelers from Florida, Louisiana, Nevada and the U.S. Virgin Islands will be advised — though not required — to obtain a negative COVID-19 test no more than 72 hours before coming to the city, or quarantine for 10 days upon arrival, the Chicago Department of Public Health (CDPH) said Tuesday.

• Last week, Missouri and Arkansas were added to the advisory list, which had been at zero for several weeks with no states surpassing Chicago's threshold of 15 cases per day per 100,000 residents.
• "We remain well below our peak rates, but these recent increases are concerning," said CDPH commissioner Allison Arwady in a statement.

Flashback: Numerous states instituted travel restrictions and quarantine requirements for domestic travelers during 2020, in part because research showed interstate travel clearly contributing to spread.

• But actually enforcing those restrictions in most states proved difficult, and by early summer 2021 nearly all rules had been lifted — save in Hawaii, where unvaccinated travelers still need to show a negative test before arrival to avoid quarantine.

What to watch: Internationally, travel restrictions are mostly receding as vaccinations spread, with Canada on Monday announcing it would end mandatory quarantines for fully vaccinated U.S. travelers on Aug. 9.

• The U.S. still hasn't reciprocated for Canadians, though the White House is reportedly considering lifting COVID-related travel bans on multiple countries.

The bottom line: Other localities may follow Chicago's lead as persistently low vaccination rates in some states result in growing outbreaks.

• But it's difficult to see the will returning for truly effective, enforceable domestic travel restrictions.