This is very interesting data,
@dad4. Thanks for posting it. After some sleep and coffee, I have some “I’m not an epidemiologist and I didn’t even stay in a Holiday Inn Express” thoughts.
What is the population distribution for the variant? The distribution of the population who are susceptible to the virus has changed dramatically with the vaccine. While the case rate is important, it is much less important than the rate of death and hospitalization. Since last Tuesday, AZ was vaccinating 55 and older. Nationally, 80% of the deaths have come from 65 and older. So, as long as we are “spitballing”, let’s say 70% of those over 65 got a vaccine and it protects them from serious illness 90% of the time (that may be high for older folks).
% of 65 and older protected from serious illness = 0.7*0.9 = 0.63 —> 0.37 of over 65’s can still get a “serious” infection
So, where we would normally expect 80 deaths of the 100 total, we get 0.37*80 or about 30 deaths. This effectively cuts the rate of death by 50%. There is a belief that the variant is more deadly. My guess is, as with most initial numbers on the disease, they are overestimating considerably. Let’s say it’s 20% more. That would raise deaths to 1.2*30 = 36 and the effective drop is 44%, not 50%. Of course, the percent of olders getting vaccinated is increasing daily. Once we get to all the 55 year olds, that’s about 90% of the deaths. I’m calling this a wash given the numbers of the variant are still relatively low. You also mention that you have a constant “doubling” every two weeks and that will obviously slow with vaccinations.
On the “bad” end, as you state, behavior can change effective R. I tend to be optimistic that this will not be a significant factor. I believe most people’s behavior is pretty much “baked-in” and not subject to external restrictions as much as those who make the restrictions would like to believe. People that want to get the vaccine (about 2/3?) will likely be cautious until they get it. Those willing to be involved in riskier behaviors are already doing so. Unfortunately, the variant will likely affect the poorer, more crowded areas even more inordinately than the initial strain. To begin with, the virus is spreading faster there - at least in our home area - and those folks appear to be getting vaccinated at a lower rate than the population.
One other thought. The variant will likely run through the younger population at a much higher rate than the original virus as they are vaccinated at a much lower rate.