And I’m back. Despite my belief that we were on the way out after a year of not seeing a new variant of concern, it seems Covid has another round left in it.

As you are probably aware, a new variant named Omicron was identified in the last week in South Africa. It appears to be more infectious than Delta and has many concerning mutations that could lead to immune escape. It’s important to remember that we are days into studying this new variant, so everything I talk about today could change.

At this point, Omicron is likely already spread through most of the world. The travel bans that some countries instituted are moronic. South Africa detected it first because they have one of the best viral surveillance systems in the world. Europe has gone back and identified Omicron cases from before the South Africa announcement.

We owe a debt of gratitude to SA for their work to quickly identify and understand what was different. In the United States, our governments at all levels have failed us by not setting up better detection infrastructure. Wastewater testing is a straightforward, objective, non-invasive way to monitor for Covid and only a handful of cities have it implemented in the US.

So what makes the experts worried about Omicron? The three significant concerns are: is it more infectious? Does it evade immunity [vaccinated or prior infection]? Does it cause severe disease?

On the question of how infectious it is, there are many strong indications that Omicron is much more contagious than Delta. In South Africa, Omicron is outcompeting Delta at a rapid pace. In Norway, there was a single infected person at a Holiday party, and they managed to infect up to 60 of the 120 people. It’s too early to compute a real R0 for Omicron, but it’s almost certainly going to be higher than Delta, which was already higher than the ancestral variant.

On the question of immune evasion we have less good data. The big concern is that the spike protein has many mutations. The spike protein is the key that helps the virus enter our cells, and if it looks too different, then our immune system will have a more challenging time identifying it. However, we have a layered immune system. Some early indications are that people who have immunity from a prior infection may be less protected against Omicron. There are also early indications that even vaccine acquired immunity may not be enough to protect you from contracting Omicron.

Again this is all early data, and I haven’t been able to find good sources for which vaccines South Africa was using and if they were administering boosters. However, based on the expert consensus I’m seeing, Omicron likely has a medium to a large amount of immune evasion.

The last question, is it less severe, is the hardest to answer. It’s actually two questions. How severe is Omicron for people with prior immunity? How severe is Omicron with people who have no immunity?

There are early, limited data from South Africa that would possibly suggest that Omicron is less severe. There are fewer hospitalizations than at this point in the Delta wave. There are a lot of confounding data points though. South Africa has a very young population, and young people have fared better against Covid. Many people who aren’t vaccinated also have had Covid in South Africa.

We have a layered immune system. So if the mutated spike protein makes it harder for our first line antibodies to stop any infection, there are beliefs that our T cells [which take longer to activate] would still be effective and prevent severe disease. This would be fantastic because when the hospitals get overwhelmed in prior waves, large amounts of people start to die.

Another promising data point from South Africa is that a number of the people hospitalized with Covid were not admitted because of Covid. They came in from another critical event [heart attack, stroke, et al.], and as part of in-processing, they tested positive for Covid. There are also questions about whether it affects young children more, but I haven’t seen anything definitive. Again all this data is very preliminary, and over the next week or two, we will have a much better understanding of what we’re up against.

This is not March 2020. We know so much more about how it spreads and how to stay safe, and we have several different treatments now. The monoclonal antibodies will probably not be as effective, but the new prophylactics from Merck and Pfizer should work equally as well against Omicron. Both Pfizer and Moderna have announced they are already working on Omicron-specific vaccines. Due to the magic of mRNA, expect to have them in production within 100 days.

At this point in time, I’m not making any changes. I went to Art Basel in Miami last week and was at a holiday party in SF last night. I restocked my supply of rapid antigen tests [you can order the Binax tests from CVS online] and will continue to be diligent about testing if I feel ill.

I know that these new developments are stressful and confusing. I’ll plan to write weekly until we better understand Omicron. As always, please reach out if you have any questions or want to chat.

Stay safe out there.