When the Covid-19 pandemic started, it was generally assumed that the only serious policy option was to “flatten the curve”: that is, keep the spread slow enough that the hospital system was not overwhelmed, until either a vaccine was developed and generally available or most of the population had caught the disease giving rise to herd immunity. Both approaches looked likely to take at least a couple of years to work.
In retrospect, this assumption was surprising. China suppressed the initial outbreak in Wuhan, as well as the spread to other provinces, and held case numbers close to zero thereafter. But for a variety of reasons, good and bad, people either distrusted Chinese numbers or thought that the lockdown measures used there couldn’t be applied elsewhere.
It’s now clear, however, that these assumptions were false. Most* developed* countries have applied measures sufficient to reduce Covid-19 from an epidemic to a set of localised clusters. At this point, a full lockdown is no longer needed. Social distancing can keep R below 1 for the general population, so that local clusters don’t grow exponentially. And, as long as the numbers are small enough, contact tracing, testing and localised lockdowns can keep the disease under control.
That’s been the experience in East Asia, Australia and New Zealand and now, it appears in most of Europe. Progress hasn’t been uniform, but no country that’s managed suppression has gone back to uncontrolled spread.
The next step, evidently is reopening borders between jurisdictions where the virus has been suppressed. The most limited form, but still a significant step would be allowing entry subject to 14 day quarantine. That could be relaxed, conditional on returning a negative test. Finally, there’s the ‘bubble’, reopening borders without quarantine or specific testing.
There’s nothing particularly novel in what I’ve written above, but I don’t think the implications have fully sunk in. Indeed, I haven’t thought them through in detail myself. To give just one example, what if the US remains isolated from the rest of the world while travel to and from China is reopened?
- Sweden didn’t attempt this, the US started but couldn’t persist long enough, and is now completely distracted by the collapse of the Trump Administration.
- It’s still unclear what’s happening in middle-income and poor countries, where lockdown doesn’t seem feasible. There’s some hope that the disease will be less severe in the tropics where most of these countries are found. Younger populations means less vulnerability. And sadly, there is already such a large toll from endemic diseases and poverty that Covid looks less exceptional.