October 23, 2020 - 7:25am

A few months ago I wrote a short piece with the trenchant headline “Memo to Donald Trump: travel bans don’t work”, about the US blocking travel from mainland Europe early in the pandemic. I wanted to revisit it, and see whether I still agreed with myself.

The piece was a little more cautious than the headline — I said that “draconian” travel bans preventing more than 90% of travel from the affected country “could delay the outbreak peak by about three weeks”. But, I implied, it wouldn’t really be possible, because people would travel around them — if you ban flights from Italy, people in Italy will hop to Switzerland and fly from there. Also, I said, in the US case at least, it was shutting the stable door after the horse had bolted, because the disease was already rampant there.

But now, if you think of any country which has done “well”, and google “[country] travel restrictions”, you’ll see they have some strict measures to prevent Covid-19 coming in from overseas.

Check it out. New Zealand: “currently closed to almost all travellers”: if you’re a NZ citizen or resident, you can come in, otherwise you have to show you’re travelling for a “critical purpose”. Even those people have to quarantine for 14 days and get tested. Entry to Australia “is closed”, which in practice means much the same as NZ. Germany has everyone from at-risk places (including the UK) quarantine for 14 days. If you’re not Vietnamese or one of a very limited set of people, you’re not entering Vietnam. Canada is a bit more relaxed but everyone, coming in from anywhere, still has to isolate for 14 days.

First: I think it’s still undeniably true that travel bans are crude. In an ideal world, you would test everyone at the airport or border, get their results in a few minutes, and then quarantine them if they need it or let them go, with precautions, if not. Some countries have done things like this. South Korea put incredibly strict requirements on travellers — location-tracking via an app, plus a huge fine and possible jail time for breaking quarantine — in place from the spring. But it’s also undeniably true that we don’t have that sort of technology in place, at least in the UK.

Looking back, I think I completely underestimated how much Covid-19 was going to upend the world. I thought it was pretty much impossible that any country would ban 90% of travel from another country. Now, lots of countries are doing it. I also worry that I may have been committing the sin of thinking “the world’s stupidest man says the sun is shining, therefore it is dark”: there is nothing worse, in the sort of liberal circles I inhabit, than agreeing with Donald Trump. Agreeing with Angela Merkel and Jacinda Adern is much more acceptable.

I have no idea whether, when the Trump ban was mooted, it was too late for even a total travel ban to have worked, or if it was remotely politically or practically possible in a huge, well-connected country like the US, or if the way the ban itself was implemented was adequate or well-thought-through.

But I think the tone of my piece implied that travel bans were stupid and that if you thought they might work, you were stupid (much as people said about masks, early on). Now, I think, most people would agree that some sort of restrictions on outside travel are vital. Back in March, though, I hadn’t quite got it in my head how different the next few months were going to be.


Tom Chivers is a science writer. His second book, How to Read Numbers, is out now.

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