Christmas with Delta, Omicron and H3N2

Iced Christmas Cookie Question Mark

People seem to be underestimating the risk of travel for the holidays. There is likely a great deal of both pandemic fatigue and temporal discounting going into these decisions, both of which skew critical thinking.


The delta surge is just starting to hit the US more broadly after being limited to smaller areas. This has led to significant impacts in hospitals in some of the hardest hit parts of the country, which has led to long wait times in the emergency room, patients being held in the emergency room because there are no beds available for them on nursing floors, and the cancellations of elective surgeries. The surge from delta alone will really start showing up in the numbers around Christmas as a result of Thanksgiving activities.


Omicron has quickly thrown a new wrench into the works. There is still a lot to be learned about this variant, but that hasn’t stopped many with large voices from downplaying it without evidence to support their claims. It’s simply too soon to make meaningful claims about the severity of disease and the risk of death from this variant.

One source that may have driven that thinking was a study from the largest health system South Africa. However, in that study the average age of patients was 34, which is known to be a much lower risk than for older age groups, thus presenting a very skewed view. The data paints a slightly different story.

When looking at admissions to different nursing unit types, the close curve between COVID incidence and hospitalizations cannot be denied. It’s also worth noting that omicron represents 98% of COVID cases in the country currently, so it is safe to assume that the majority of these are due to omicron. In addition, it should be noted that the downward curve at the very right likely represents incomplete data reporting, which is known to lag for days.

There are also claims being made that there aren’t omicron deaths. The fact is that there is a long interval between when a case is reported and when a death is reported. Some of the deaths are starting to show up in the data..

The truth is that there simply isn’t enough data yet to claim that omicron is a mild form of the disease, but that narrative will drive some people to make very bad decisions thinking they will be safe. The New York Times contains an excellent piece from a couple of days back with more detail on what is known.

H3N2 Influenza

The influenza season also normally starts to grow quickly about this time of year. Thanksgiving and Christmas are likely two major times of long distance spread across the US. Last year, influenza activity was low, due to high influenza vaccination rates, a lower severity season in the southern hemisphere (theirs precedes that of the northern hemisphere), and people were taking additional precautions for COVID, such as social distancing, masking, and frequent hand hygiene. In addition, by keeping the numbers low early on, that prevented exponential growth of influenza cases.

There is no mask usage data for this exact time last year, but one can safely assume that it was likely as high as the highest point around the beginning of 2021. Mask use has decreased considerably since, part of it due to the bad messaging that those vaccinated did not need to wear masks, which accounts for the very large dip in use. It is worth noticing the correlation between the drop in mask use and the rise in cases as well. Mask use by state can be found be found on the graphs for the respective states at the top of the page.

The best way to think of the situation is that there are two separate pandemics superimposed on each other, delta being quickly followed by omicron. The wildcard is H3N2, which is beginning a sharp climb in the US.

INFLUENZA Virus Isolated

A comparison of this season of influenza like illness to prior years suggests at best this may be a moderate year, but potentially worse.

Percent of Visits for Influenza-like Illness (ILI) Reported by the U.S. Outpatient influenza-like Illness Network

H3N2 caused an influenza pandemic in 1968 leading to an estimated 1 million global deaths. That seems small compared to the 5.4 million recorded deaths from COVID, which is likely a gross underestimate. However, there are some troubling signs with H3N2 this year.

The influenza vaccine was formulated to protect against H3N2, but a new variant of it emerged (Darwin) from Australia that appears to evade vaccine. This is causing an epidemic of influenza in South America. What is troubling about that is it is occurring outside of their normal influenza season. This suggests a significant year for influenza, so we can at least expect two superimposed pandemics and an epidemic.

Decision Analysis and Temporal Discounting

Christmas is rapidly approaching and changing plans might be a difficult decision. Hopefully this simple version of a decision analysis tool will help. First though, the behavioral psychology or behavioral economics concept of temporal discounting needs to be addressed.

Temporal discounting is simply the tendency of people to value something in the future less than something in the present, although they may have exactly the same value. This is a particular problem in American society, as evidenced by how the average household carries over $6000 in credit card debt. This shows a clear tendency to pay much more for something to have it now (because of the high interest rate on a credit card) versus waiting to pay for it in full.

One tool of decision analysis is known as a two by two table. I will avoid the technical terms to get to the point. The top contains the two unknown possibilities (the virulence of omicron) and the left contains the choices of gathering or not. Inside the table are some of the various outcomes.

There are two tables to take into account temporal discounting. I’ve highlighted the words in red that differ between them. It contains three general categories of outcomes to consider.

The risk of infection should be relatively obvious. Social costs in the short term tend to focus on those directly involved in the decision, however, in aggregate the social cost could be considerably higher for the same group of individuals because of how the actions of the rest of society affect them. The same is true for economic costs. Those two variables are a perfect example of how the decisions of others can affect them directly. Much of the narrative of people who aren’t taking precautions focus simply on the short term risk of infection for them as an individual.

When thinking through this framework, it becomes easier to understand the differences between the different combinations. Obviously continuing with plans if omicron has high virulence is a very bad choice and the delaying plans is the best choice.

It’s worth a quick mention of the social and economic costs that seem to be overlooked. If a family member becomes ill and requires hospitalization, there is a very large economic impact on the family. If the family member dies, the economic and social impacts increase even further.

Testing Problems

Some may think that relying on testing and their vaccination will provide adequate protection. However, we know that omicron can evade vaccination, although the vaccine does reduce the risk of serious illness. There is a major problem with testing. “FDA finds 3 COVID-19 tests that fail to detect the omicron variant.” False negative tests could cause a disaster among people who think that they had tested negative.


It would be best to consider delaying holiday celebrations until more is known. The rate of spread of the omicron variant is incredibly alarming. The best plan would be to limit contact to those in your immediate household.

If you choose to travel, wear a respirator in any indoor (and possibly outdoor) venues. It may be worth doing around those you are planning to visit as well for the reasons listed above. It may also be helpful to look at some new reports from the federal government. There isn’t a single page with a link for each state, but they are easy to find using the search term “State Profile Report (SPR)” and the name of the state you want to find.

Most importantly, don’t gather with the public. At a bare minimum, avoid Christmas parties. These are very dangerous activities almost guaranteed to cause rapid spread.

Change your plans. Throttle them back. Protect the ones you love and everyone else around you.

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