Covid-19 in Fairfax County, Virginia, January 2022

January 31

Now that we are at the last day of January, the Covid situation in Fairfax is becoming clear: daily cases continue to decline from their all-time high levels around the turn of the year, and daily hospitalization and death rates per case have remained relatively low, several times lower than at any previous time in the pandemic. The graph shows the data for Fairfax from the Virginia Department of Health. The Omicron surge looks like it will last around 6 weeks, with the peak all-time high level of over 1500 new cases per day extending over a 3-week period from late December to mid-January. The dark and light green lines show that hospitalizations H track cases C with a rate of 1 H for every 380 cases. The average hospitalization rate never exceeded around 6 per day here. This is over 5 times better than the 1 H in 70 C for the Delta surge last summer, and more than 10 times better than the 1 H in 33 C during 2020 prior to vaccinations. Not surprisingly, daily deaths D have also remained quite low, with an average running around 1 or fewer deaths per day throughout (the spike around day 180 is artificial, due to VDH adding in prior deaths that were late in getting counted). The death rate is too low to measure accurately, due to daily statistical variations. It is 1 in every few thousand cases; the thin model red line in the graph shows the predicted deaths if I assume that there is 1 death for every 2000 cases. For comparison, the death rate for the ordinary seasonal flu is near 1 in 1000 cases.

Jan. 31, 2022. The points show daily case, hospitalization, and death data due to Covid-19 in Fairfax County, Virginia, between July 1, 2021, and Jan. 14, 2022 (source: Virginia Department of Health, VDH). Case levels are undercounts since they only include cases confirmed by reliable PCR tests and do not count untested or home-tested cases. The solid blue, green and red lines show 7-day averages of the data. The light green and red lines show my model predictions as described in a previous post, but with revised ratios to fit the current data. The magenta line shows the Delta + Omicron double exponential model described previously, using an Omicron case doubling time of 4 days to best fit the data through Dec. 31. The “width” of the Omicron curve is around 3 weeks, in contrast to an 8-week duration with previous variants. We do not yet know what the “tail” of the curve will be–how quickly will cases drop back to November levels?

Consequently, the present situation with Covid-19 in Fairfax county is actually relatively good. The recent highly contagious variant has caused lots of cases but relatively little serious illness and death here. Currently, Covid-19 seems to be no more harmful in Fairfax than a severe season of the conventional flu (which can kill a comparable or even larger number of people). It is known from studies elsewhere that vaccination, especially if a booster shot is received, is HIGHLY EFFECTIVE in preventing both the disease and in preventing serious complications or death from the disease. The VDH data by vaccination status shows that in early January at the peak of the recent surge fully vaccinated people were 20 times less likely to be infected than the unvaccinated. Even in highly vaccinated Fairfax County (76 percent fully vaccinated and 38 percent boosted), by far the most H and D events were among the unvaccinated (which still number around 280,000 people in Fairfax County). Given the differences in case rates and population sizes, the unvaccinated population has driven over 80 percent of new cases during the recent surge with more than half of the cases coming from the younger 18-49 age group. Fortunately, the new variant is sufficiently mild that even the unvaccinated are seeing better H and D rates than they had earlier in the pandemic, since the overall rates for all cases apply to the unvaccinated group, since they are generating the most cases.

As has been the case throughout this pandemic, the per capita C, H, and D rates for Fairfax county have been much lower than the values for the USA as a whole. The current per case death rate for the USA (2500 deaths per day now due to 800,000 daily cases 2 weeks ago, or 1 D per 320 cases) is around 6 to 10 times higher than the per case death rate in Fairfax (1 death per day for 2000 to 3000 daily cases 2 weeks ago). That means that lots of lives are being lost in the USA that quite possibly could have been prevented.

We don’t know what some future variant of Covid-19 might bring. But at the present, it seems like we may have turned the corner on this disease, at least in Fairfax County. The disease itself has become milder, vaccinations are very effective for those who receive them, and we may be approaching the point when most people can and should return to a more normal life. If only both liberal and conservative politicians could come together, take a hard look at all the data, and make common sense decisions on how best to minimize illness and disruption and return to a more normal kind of life. We need not be excessively cautious, but we should not abandon all caution either. We could learn to live with this pandemic better, neither showing excess fear nor excess dismissal of it.

To me the basic science and data related to this pandemic show that maximizing the number of vaccinated people remains one of the best ways to protect the most people with the least harm. Masking also has its place, especially when cases are surging, to protect the most vulnerable. People need sane guidance concerning for which situations it is appropriate or not to use masking. Avoiding crowded, poorly ventilated indoor spaces is a safe step for the vulnerable older or immunocompromised population; others need to make decisions based on common sense and knowledge of the current level of risk.


The next page gives my earlier assessments for Jan. 15 and Jan. 21. Click on p. 2 below to get to these.