Omicron is the latest SARS-CoV-2 Variant of Concern (VOC), initially discovered and sequenced in South Africa.1 It is considered concerning because of the number and type of mutations—32 of them on the spike protein. Spike is the bit of the virus that a) gives the virus entrée into the cells, which affects transmissibility, and b) is used as the model against which to build vaccines. The worry is that the high number of mutations will make the virus must more transmissible and/or make it easier for the virus to escape not only innate immune response but the immune response acquired via previous infection and/or vaccination.
It’s pretty clear already that Omicron is, in fact, much more transmissible than either the original virus or today’s most prevalent variant, Delta. One graph I’ve seen indicates that Omicron took less than 20 days to reach a greater than 90% share of all sequenced cases in South Africa, whereas Delta took almost a 100 days to do the same. Don’t quote these figures because I’m just eyeballing pictures, rather than tallying tables of data, but its possible Omicron could out-compete Delta four times as fast as Delta out-competed other variants. In other words, if we could make direct comparison between the virus’s impact in South Africa to what will happen in the rest of the world, in a few weeks Omicron will be the only variant that matters.2
As for the ability to escape immunity—innate or acquired—no one knows yet, though preliminary evidence suggests reinfection rates with Omicron are high. Should it prove to escape immunity I think it’s likely a) it will only be partial and b) many of the treatments—particularly the corticosteroids and IL6 receptor blockers—will work. The antivirals may still be effective, depending on the mode of action.3 Also, if mRNA vaccines do turn out to be a little less effective against Omicron than against the Delta variant, both Pfizer and Moderna have suggested they could produce tailored vaccines within a 100 days or so.4
My real question about Omicron concerns virulence: is it more, less, or equally as deadly as other variants? In this regard I feel a very faint hope. There are some anecdotal reports from South Africa that it could, in fact—at least in the acute phase—cause a milder illness than other variants. Patients’ symptoms seem to be not only slightly different—fever, elevated heart rate (especially in the young), no loss of smell, not much lung involvement—but milder; they recover faster. (Having said that, it’s important to note that the group initially infected with Omicron were mostly university students—a very different health profile to the general population.) If the story of Covid were only about the acute phase, and if these early anecdotal reports were borne out by further study, then this would be fantastically good news: it could be the beginning of the long, winding road to Covid becoming no more worrisome than a bad cold.5
BUT. Okay, two buts. One, it may not be borne out when expanded to a wider population. And, two, the story of Covid is also about its chronic phase: Long Covid.
The data we have about Long Covid isn’t very good (in the sense that we can only talk about those who have been diagnosed with a positive PCR test—which could be a fraction of the whole). But what we do have suggests that more than one third of those testing positive for SARS-CoV-2, even those whose symptoms were mild, still have one or more symptoms 3-6 months later. Some people have Long Covid a year and half after diagnosis and it seems worryingly likely that for some it is a form of ME/CFIDS, which can be a debilitating, life-long condition. Because Omicron is newly sequenced, there’s absolutely no way to tell how or whether Long Covid percentages will differ. That could end up having a massive long-term impact on the overall health (and therefore healthcare burden, and therefore economy) of a population.
In conclusion: it’s probable that Omicron is more transmissible than other variants but even that is not yet certain. The rest is a series of questions that will be answered one by one over the coming weeks and months—and those answers could be a mix of good news and bad news. We just don’t know.
So for now: get vaccinated, get boosted, wear a mask, keep a couple of rapid home tests close by and test yourself and other members of your household if you’ve been exposed and/or show any symptoms.6 Above all: don’t panic. Precautions that work against Delta—masking, social distancing—will work against Omicron. And while, sure, it’s possible we could all die tomorrow of some super-virulent super mutation it’s also possible that Omicron could be an early holiday gift: the faint and tiny glimmering of a possibility that Covid may become a minor inconvenience, nothing worse than a cold.
1 Does it mean that’s where it originated? Not necessarily.
2 For comparison, the Delta variant is 70% more transmissible than the original. And of course we can’t compare South Africa to, say, North America directly: the demographics there are completely different. And the initial group of those infected with Omicron were university students—a really different profile. Nonetheless, I think by the New Year, Omicron may very well be synonymous with Covid here, in Europe, and almost everywhere.
3 but to what degree? The Merck antiviral pill has now been found to be only 30% effective against the symptoms of Covid, but Pfizer’s protease inhibitor, Paxlovid, which, if administered in the first five days, cuts the risk of hospitalisation by an almost unbelievably impressive 89%, is still looking very good. Though it has not yet, to my knowledge, been tested against the Omicron variant, given its mode of action I doubt it’s effectiveness will be massively reduced.
4 I’m assuming right now that AstraZeneca can, too. If you celebrated Thanksgiving I hope you gave thanks to medical science; I certainly did.
5 I repeat long. I repeat winding. There are many coronaviruses—including about 20% of those that now cause some of the illnesses lumped under ‘common cold’—that probably started out as deadly pandemics. (Possibly, for example, the so-called Russian Flu of the late 19th century.) But it doesn’t happen overnight. It can take decades.
6 You can buy them at any pharmacy. Buy a few. If you test negative, test again to be sure. If you test positive, go get a PCR test. Edited to add from someone more knowledgeable than me: “In many cases (for example if you are symptomatic, or have a known high risk exposure) a positive antigen test can be regarded as accurate and a confirmatory PCR test is not needed or recommended. Talk to a healthcare provider to see whether one is needed.”