Cases and deaths keep rising. The 7-day average for cases is 170,856, for deaths it is 1,511. Still there is some good news mixed in. The rise in cases has been slowing down. Looking at week-over-week numbers (comparing each day to the same day a week earlier), the rate of increase has steadily dropped from about 40% two weeks ago to about 15% yesterday. We haven’t yet plateaued, but we may be headed in that direction. Deaths, on the other hand, are accelerating. They’ve gone from a week-over-week increase of about 10% up to over 30%. Here’s a chart showing the period since September to make the changes in acceleration clearer.
The slow down in cases is most likely due to increased restrictions in various states along with increased caution from individuals. As cases and deaths rise, people become more concerned and so are better about wearing masks and avoiding crowds. In the previous surges, this sort of slowing would indicate that we were reaching a plateau. Even if cases plateau, we should expect cases to continue rising for one to two weeks. However, there are circumstances that cloud the picture in this case.
First, there is the continued pressure of winter. With colder temperatures, people tend to stay inside more. As we get tired of precautions, we can’t simply move our activities outdoors.
Second, there are the holidays. Many people will still gather for Thanksgiving even if they are taking precautions in other ways. We are likely to see many super spreader events as people gather and then carry infections back home. It will take a couple of weeks for these to show up in the data, but there is a real danger that we will see another surge before this one has fully finished.
Third, a significant portion of the slow down is due to Illinois. Illinois has had the highest case numbers in the country for some time. Cases there had been growing quite rapidly but over the last 10 days plateaued and even decreased some. Their week over week case increase number was 60% on November 11 but has dropped to -3% for the last few days. Because they have so many cases, this drop has a real impact on the national numbers. There are similar patterns in other states in the northern plains and upper midwest, but states outside of this area continue to rise rapidly. Much depends on how the virus behaves in states outside this region including in many of the highest populations states such as California, Texas, Florida, New York and Pennsylvania. Currently, these high population states are all still accelerating.
Finally, the holidays will interfere with data gathering. People are less likely to get tested on a holiday and people who record deaths and cases are more likely to be away. We’ve seen this effect on earlier holidays and none of those were as big a deal as Thanksgiving and Christmas. Be skeptical of sudden drops in the numbers this week.
In other good news, we have preliminary data on another vaccine candidate, this one from Oxford/AstraZeneca. The efficacy looks good, though it may not be as high as the Pfizer and Moderna vaccines. However, distribution is even easier as this one only requires refrigeration rather than freezing. The topline efficacy number is around 70%, but it may turn out to be quite a bit higher depending on some factors that we don’t know yet. If you want to read more about this, I again recommend Derek Lowe’s blog. The relevant article is at https://blogs.sciencemag.org/pipeline/archives/2020/11/23/oxford-az-vaccine-efficacy-data . Even a 70% efficacy rate will have a major impact and this candidate will be more easily distributed in regions of the world that have less access to advanced refrigeration, so this is very good news.
That’s all for this post. Enjoy the upcoming holiday, but try to do so in the safest way you can.