December 11, 2021
At this point, we still don’t know very much about the omicron variant, except that it spreads far more quickly than the delta variant. The data show a sharp upsurge in COVID-19 cases in South Africa, most of which seem to be omicron. There have also been several instances of what turned out to be super-spreader events in Norway, Denmark, and the UK where a ridiculously high percentage of the attendees became infected with omicron. (At a Christmas party in Norway, 70 of 120 guests tested positive.)
The variant also seems to be able to get around the immunity built up from vaccines or prior infections. In principle, all the people infected at the super-spreader event in Norway had been fully vaccinated, since this was a precondition for admission. In South Africa, many of the people who have been hospitalized with infections already should have had some immunity from prior infections. In short, we can be pretty confident that omicron spreads much more quickly than delta or earlier variants.
That is the bad news with omicron. The good news is that the evidence to date indicates that it is far less severe than delta. Most of our evidence on severity comes from South Africa, where it was first detected. The reports from hospitals there indicate that a much smaller percentage of the people who get infected need oxygen and end up in intensive care units. It also seems that a much smaller percentage are dying.
The country has an upsurge in reported cases that began two weeks ago. Yet, there is no clear uptick in COVID-19-related deaths. The figure for the most recent day (December 10th) was 20 deaths, which would be the equivalent of 110 deaths a day in the United States, less than one-tenth of our current number.
It is possible that we will have to wait longer to see the effect of omicron on serious illness and death. There is typically a substantial gap between when people are infected and when they get seriously ill or die. Also, the case numbers have continued to grow rapidly, so two weeks out from the current levels we may be looking at many more people in intensive care units or dying.
It is also pointed out that most of the cases in South Africa are younger people, who presumably are at less risk from COVID-19. This is an important caution, but it’s worth thinking about this issue more closely. Younger people are generally not isolated from the rest of the population. People in their twenties or thirties who got infected two or three weeks ago surely came in contact with parents, friends, and coworkers who are older.
If these older people either did not get infected or are not showing up at hospitals with serious symptoms, then it would seem to imply that omicron does not pose an especially serious threat to older people. There may well be more to the story that will become apparent further down the road, but it isn’t plausible that, at this point, only younger people in South Africa have been exposed to the Omicron Variant.
The Spread of a Less Harmful Variant
Recognizing that we still have little basis for assessing virulence, it’s worth considering what it would mean if omicron does spread widely throughout the world, which seems likely, and it is considerably less harmful than delta. Of course, the big issue is how much less harmful. If three times as many people get infected, and omicron is half as likely to lead to hospitalization and death, we would still be looking at a pretty awful story.
One thing that is very encouraging on this front is the experience of the people at the super-spreader Norwegian Christmas party. These were all vaccinated people and apparently in relatively good health, but it seems that none of them developed serious symptoms and needed to be hospitalized. If this is a general pattern, then we can expect that fully vaccinated people, without serious health conditions, have little to fear from omicron, perhaps even less than they did from delta.
While that is a good chunk of the population in the US and other wealthy countries, this still leaves the elderly, people with health issues, and the unvaccinated. We will probably have to see how things play out in South Africa and elsewhere to get a better sense of what to expect in the United States, but from what we have seen to date, they may not face a bad story either, or at least no worse than the one they faced with the delta variant.
Here also the limited information from South Africa is encouraging. Just 30 percent of its population is vaccinated and less than 26 percent is fully vaccinated. This means that a large number of unvaccinated people must be getting infected with the omicron variant. Yet, we are not seeing its hospitals fill up with seriously ill patients, and its death figures are still relatively low. Again, this could change in the days ahead as the disease has had more opportunity to progress in people recently infected, but it is at least plausible that even people who are not vaccinated have less to fear from omicron than delta.
What Happens if a Mild Omicron Variant Displaces Delta?
If it proves to be the case that omicron poses substantially less risk of serious illness or death than delta, and the difference more than offsets the increase in the number of infections, then the spread of omicron in the United States may be very good news. It will almost certainly mean an increase in the number of infections since it will spread more quickly, but it would mean a reduction in the number of hospitalizations and deaths.
There will be a huge question of timing. Even if the risk of hospitalization and death is only a fifth as great as with delta (a number pulled out of the air), if it spreads ten times as quickly, it will mean twice as many people ending up in hospitals and ICUs. This means that it would still be necessary to take steps to limit the rate at which it spreads.
However, if it turns out that the difference in the severity with delta is larger than the difference in spread, the omicron variant may prove to be very good news. It can lead to a situation where we do achieve something close to herd immunity, with most of the population either being vaccinated or having an infection with omicron. (The evidence from South Africa is that prior infections with other variants do not provide much protection from omicron.) Getting to that point would be a huge victory.
Of course, we are quite far from anything like herd immunity at present. The delta variant is still by far the dominant strain in the United States. We are averaging more than 120,000 cases a day and more than 1,200 deaths. Hospitals and ICUs are packed in many parts of the country.
The story continues to be overwhelmingly one of unvaccinated people getting seriously ill and dying. For whatever reason, we continue to see large numbers of people who refuse to take the pandemic seriously. Their risk affects not only their own lives, but also the health of their family and communities, as many hospitals can no longer provide normal care to non-COVID-19 patients. This is a very unpretty picture, but there is at least a possibility that the spread of omicron will make the situation better rather than worse.