Miguel Candela/SOPA Images/Sipa USA via AP Images
Passengers social distance at Hong Kong International Airport. Hong Kong, known for having one of the most restrictive coronavirus quarantines in the world, is currently seeing daily record cases.
The countries that best handled the coronavirus pandemic in 2020 and most of 2021 followed a “Zero COVID” strategy. The idea was that with aggressive hygiene measures, including strict lockdowns if necessary, coupled with a system of mass testing, tracing the contacts of positive cases, and putting anyone with the virus in quarantine, you could stamp out community spread. Then, once the virus was no longer circulating, you could substantially relax the domestic containment protocols, while maintaining strict quarantine requirements for anyone entering the country, and life could return to something like normal.
Variations on this strategy, which was devised and adjusted on the fly by Chinese authorities very early in the pandemic, worked brilliantly for countries like South Korea, Taiwan, Vietnam, Australia, and New Zealand. While the United States suffered a trainload of totally unnecessary death every day for the first year of the pandemic, these nations dodged almost all infection with diligent policy.
Unfortunately, Zero COVID has since collapsed or been abandoned in almost all these nations, thanks to the ultra-contagious omicron variant, the spread of the virus into several animal species, and a gradual erosion of popular support. The last holdouts—South Korea, Australia, Japan, and now New Zealand and Hong Kong—have all seen explosions of uncontrolled spread. Only Taiwan and mainland China soldier on, and in both cases it appears to be only a matter of time before Zero COVID falls there, too.
Mass vaccination and broad rollout of the new antiviral medications are now the best strategies to fight COVID. Masks and other containment measures can help, but they can only be adjuncts now.
The main problem is that omicron is just too dang contagious. Where the original coronavirus had a reproduction number (or R0) of around three in a typical setting (meaning each infected person would spread it to three more people, on average), and an incubation period of about five days, a case of omicron spreads to about eight to ten people with an incubation period of just three days. That makes it arguably the most contagious virus in human history—measles and chicken pox have a higher reproduction number, but their incubation periods are typically 10 to 12 days and 14 to 16 days, respectively. If you do the math, omicron probably spreads faster than either one.
Other species that have contracted the virus make Zero COVID even more difficult. It has been found circulating in white-tailed deer, mink, dogs, cats, mice, and many other animals, all of which raise the risk of animal-to-person transmission, which is what started the whole pandemic in the first place. (This also makes fully eradicating COVID totally impossible.)
A related problem is political exhaustion. Zero COVID works best with hair-trigger aggressiveness. You ideally want to catch every single positive case, so that lockdowns and such are as short as possible. That implies highly coercive measures. But the more contagious a virus gets, the harder it becomes to drive R0 below one (the point at which an outbreak will burn itself out eventually). If you land just slightly short of the mark, instead of a sharp but uncomfortable two to four weeks of strict containment, it drags on indefinitely.
As more and more people are vaccinated, the social benefits of policies like lockdown are smaller and smaller.
And these policies are very uncomfortable. Zero COVID requires lengthy quarantines for people entering the country, dealing the tourism industry a heavy blow. Forced quarantine for exposure disrupts personal lives, government operations, and businesses. If a real lockdown is required (which has never happened anywhere in the United States at any point in the pandemic, by the way), it means forcing people to stay at home with fines or other punishment, with schools and businesses closed, many lost jobs, high rates of depression and other mental-health problems from the social isolation, and so on.
Nations have learned to support these policies if they believe in the light of “no community spread” at the end of the tunnel, but they sour on them quickly if they don’t seem to be working. Even relatively mild measures have sparked protests in South Korea, Australia, and New Zealand. It’s not a coincidence that the only large non-island country that has managed to sustain Zero COVID is also the one with a dystopian police state apparatus—China. There, people are forced into their homes or quarantine by the millions (at gunpoint if necessary), dragnet surveillance is used to catch any noncompliance, and rule-breakers are brutally shamed.
Vaccines have further undermined popular support for Zero COVID. As more and more people are vaccinated, the social benefits of policies like lockdown are smaller and smaller, and people become less willing to sacrifice their personal pleasures and mental health for the greater good—especially when many people most at risk stubbornly refuse to get a virtually risk-free shot because they’ve swallowed crackbrained Facebook memes or Tucker Carlson tirades hook, line, and sinker.
Once community spread takes hold, then the brute mathematics of viral transmission takes over. The outbreak will continue to fester until it has infected enough of the population that R0 will be driven below one because of infection-induced immunity—thus the wild up-and-down cycle recently seen in the United States and Europe. Masks and similar social-distancing rules can flatten the curve of infections, which can be important for keeping the medical system from being overwhelmed, but they have failed to reduce R0 below one when confronted by omicron, outside of a couple of rapidly fading exceptions (Taiwan looks likely to give up within weeks, and the Chinese government has lost control in Hong Kong, which means mainland spread is probably inevitable).
It follows that the best way to be prepared for omicron was to have the highest possible rate of vaccination—especially with a third dose in as many people as possible, because, as recent studies have demonstrated, a booster provides protection that is far more durable and broadly effective than two doses. As usual, the United States is a humiliating international laggard in this respect, landing far behind peer wealthy nations and perhaps half of middle-income countries.
Cuba in particular did remarkably well by hurriedly vaccinating children—some 96 percent of those above the age of two. In addition to preventing the vast majority of serious illnesses and deaths, this cut omicron transmission substantially, and hence reduced R0. As a result, Cuba’s omicron wave was smaller and far less deadly than the one that crushed hospitals across the U.S.
It’s important to be clear that this is not admitting the “let ’er rip” crowd was correct back in 2020. Attempting a herd immunity strategy in early 2020 to protect the economy, as some Swedish health officials and many American conservatives advocated at the time, was equal parts murderous insanity and impossible. In the first place, it was deranged to throw vast populations at a wholly novel virus before the medical establishment even had time to figure out treatment rules of thumb (like “proning” COVID patients onto their stomachs so they could breathe more easily, which markedly improved survival rates). Second, most people were so frightened back then that they did all they could to avoid infection regardless of government rules, creating the exact same economic disruption as Zero COVID would have done without the necessary rigor to stamp out community spread.
The libertarian crackpots behind the so-called “Great Barrington Declaration” in October 2020, which similarly argued for letting the virus spread on purpose, were also out of their minds. Zero COVID was manifestly possible back then with sufficient determination, and vaccines were not available yet.
But it’s not 2020 anymore, and omicron is not wild-type coronavirus or the delta variant. The greatest virtue of Zero COVID, and containment policy generally, was buying time. Every day an infection could be avoided was one day closer to building immunity with mass vaccination instead of mass infection. Today we have the vaccines, miraculously ready for deployment in less than a quarter of the previous record time—a full three-dose sequence of which cuts one’s risk of death by over 99 percent. We also have new antiviral medications that cut the risk even further if they can be administered quickly.
In other words, Zero COVID served its purpose. It saved millions of lives, and it would have saved millions more if other countries could have gotten it done. But today, alas, just about everyone on Earth is likely to be exposed to the coronavirus sooner or later, if they haven’t been already. The key task for governments around the world is distributing vaccines everywhere (and especially helping Africa with administration), and sharing antivirals as widely as possible as production ramps up. At this point, it’s the best we can do.
