Of the 63.4% of Danish Covid-19 cases from the first week in February for which the Statens Serum Institut has been able to sequence the full genome, 30.9% were of the B.1.1.7 lineage. That’s up from 3.8% just four weeks earlier, so B.1.1.7 is rapidly headed toward becoming the dominant variant in the country. The number of B.1.1.7 cases is still pretty small, though, and at the current growth rate it will be months before the variant is as prevalent in Denmark as the old-school version of the virus was in December. But the current growth is occurring amid a strict lockdown that has been extended through the end of this month, and that can’t be maintained indefinitely. “If we look at our models,” Statens Serum Institut epidemiologist Camilla Holten Moller told Science magazine a couple of weeks ago, “this is the calm before the storm.”
Then there are the mutations encountered in Brazil and South Africa that appear able, at least partially, to evade the immunity provided by previous infections and vaccines. Because B.1.1.7 is so contagious, it seems likely to shove most other variants aside. There have been eight cases of the South African B.1.351 variant identified in Denmark, for example, but all were connected to overseas travel, and it doesn’t seem to have spread. However, Danish researchers have identified 72 B.1.1.7 cases in which the virus has a spike-protein mutation similar to the one on the South African variant. It’s too early to determine what impact this will have, but it doesn’t seem good.
Behavior
In the U.S., which sequences a far smaller percentage of Covid-19 test samples than Denmark and is thus flying relatively blind on B.1.1.7 and other new variants, state and local authorities have been relaxing Covid restrictions in the face of falling overall case numbers. The effect of these relaxations has probably been limited so far, given how terrible the weather has been across much of the country. According the Dallas Fed’s Mobility and Engagement Index, based on mobile-device location data, Americans have been out and about less (relative to a year earlier) over the past month and a half than at any time since late last spring.
The weather is eventually going to improve. Until now, though, Americans seem to have been slower about jumping back into action when Covid-19 restrictions are lifted than people in some European countries. This is partly just because there’s been such a wide range of Covid policies across different states and cities. But OpenTable Inc.’s city-by-city restaurant data indicate that there may be more to it than that.
Germany was spectacularly successful at warding off the first wave of Covid-19 last spring. After that, though, life in the country went back to something approaching normal, setting the stage for a very tough fall and winter. In the U.K., the sudden resurgence of Covid cases in December surely owed a lot to the rise of the more-contagious B.1.1.7 virus variant, but the alacrity with which people there embraced the easing of lockdown restrictions in November must have contributed, too.
In the U.S., a mix of distrust of official pronouncements and the ease with which many people have been able to switch to an all-remote, all-delivery lifestyle seems to have resulted in a different pattern in which life in much of the country never came close to returning to normal and probably won’t for a while yet. This may help keep things from getting out of hand this spring.