Data insight

COVID waves: Europe and US compared

A major bout in Europe, with case growth reversing in the US

The US and Europe have gone through several waves of COVID thus far. These waves have been roughly synchronized. But their amplitudes are different and there have been large differences when we dive into the subnational/regional dimension.

New cases per capita

The visualization below shows weakly cases per capita in the US (and its Census Bureau regions) and Europe (and its regions) as mirror images. The values are stacked and should be read as contributions to the total case rate.

COVID waves across the US and Europe have been synchronized to some extent. This can be explained, in part, by common drivers:

  • Seasons. As US and Europe are both in the Northern Hemisphere, the end-of-year winter period helps fuel cases as people spend more time in indoors. 
  • Holiday and school calendars. Holiday schedules and school calendars show similarities – thus contributing to the spread when adults return to work and kids to school when schools reopen.  
  • Variants and fatigue. The introduction of more contagious variant is also a common factor, with pandemic fatigue (which is also shared across the pond) assisting in the spread.  
  • Testing. Differences in testing also help explain things. A key reason for low case rates in both the US and Europe during the first wave was limited testing.

But notable differences exist. Unlike the US, Europe did not have a spike in cases in July-August 2020. While the winter of 2020 was much more intense for the US, the surge in Europe started somewhat earlier (albeit from a lower base). Same goes for the delta wave: more pronounced in the US, but started sooner in Europe. We’re also seeing a disconnect between the most recent surge in Europe, which has manifested itself in the US in a flattening out of case growth.

It’s interesting to also look underneath the aggregate picture (see also charts at the very bottom of this post). In the US, the Northeast was driving national case rates during the first wave. During summer 2020, the South took over. During winter 2020, all regions saw major bouts. Of late, the South has been a main driver.  The consistently large contribution of the South to national case rates is remarkable (the exception being the first wave).

In Europe, the first wave was driven by all regions simultaneously, except for Eastern Europe. There was no summer wave in 2020, but soon after all regions saw a major spike led by Western Europe, followed by an even-greater spike in Northern Europe. Around April 2021, Eastern and Western Europe saw another surge, which was more muted elsewhere. The most recent bout has been particularly pronounced in Eastern Europe.

New deaths per capita

How about the mortality impact? It is striking that even though the measured intensity  of cases was greater in the US, the impact on mortality turned out equally and, at some points, more pronounced in Europe.  Timing-wise, Europe generally led the US on the mortality impact (following the same pattern we observed on cases). The exception is the most recent wave (August onwards), where differences in vaccine coverage have played a role. With the recent bout in Eastern Europe, however, mortality rates are rapidly catching up with those of the US.

 

 

During the early stages of the pandemic, the impact on the US Northeast and everywhere in Europe (with exception of Eastern Europe) was very large. At later stages, other regions on both sides of the pond became more equally affected. Northern Europe and Eastern Europe saw a huge spike during January and April of 2021. Eastern Europe is seeing a huge spike right now. Finally, note how the rise in mortality in the US during the most recent wave has been largely driven by the South. 

Note: Below are two more visualizations showing developments for cases and deaths side-by-side for the US and then Europe.