Before #COVID19, the thinking in global health was that travel measures carried harms for little benefit.

Then the pandemic happened and turned that upside down. Why? I took a look at Vietnam, a country of 97 million with 2700 Covid cases & 35 deaths https://www.vox.com/22346085/covid-19-vietnam-response-travel-restrictions

For context, lots of countries did travel measures - they were the 2nd most common policy govs adopted when the pandemic took hold - so what was diff about Vietnam? https://www.nature.com/articles/s41562-021-01079-8/figures/3

Well, it's almost impossible to go there now. Since last March, they've cancelled commercial flights for months on end. Ltd travel resumed but mostly for experts/biz people, only from select countries. You need gov permission to enter & 2 weeks of state-monitored quarantine.

Where other countries enacted travel measures late, filled them with loopholes, and only targeted select countries... Vietnam walled itself in. Unlike US/Europe, they didn't drop the restrictions when cases fell to zero. And that's an important lesson.

As @KarenGrepin told me: “The value of border restrictions goes up the fewer cases you have.”

The restrictions work best if they’re implemented when they most seem like overkill, @markjit said.

They need to be put in place before (or after) community transmission.

Another thing about travel measures: they have to be supported by a robust domestic public health response. In Vietnam, there was lots of testing, extensive contact tracing, enforced quarantine and isolation, etc. Details here: https://www.vox.com/22346085/covid-19-vietnam-response-travel-restrictions

What can we learn from Vietnam’s Covid experience with travel measures? This doesn’t mean they should now be the default going forward, @LawrenceGostin @shoffmania @profplum8 warned. (Details in the story)

But Vietnan’s Covid response defied expectations in many ways. Even the economy grew in 2020. We have so so much to learn from them, especially as countries scramble with new travel restrictions in the face of variants.

Story here, with reporting from @JohneeNguyen @ThuyDoTiDi and photos/photo editing from @PhamHaDuyLinh @kainazamaria that'll take you to Hanoi https://www.vox.com/22346085/covid-19-vietnam-response-travel-restrictions