I’ve owned all of two cars in my life. The first one I owned as a 1995 Toyota Corolla. In late December 2012, I was driving to work along a windy road in Ballston Spa, New York, when I hit a patch of black ice. My car started to head inexorably towards a nearby guard rail. Once I accepted that that was going to happen, a weird sense of calm came over me: It’s only a guard rail, not another car; the guard rail is keeping my car from going into a ditch, with me inside; my car has a bumper, a crumple zone, and driver side airbags, and I’m wearing a seatbelt. The car will probably end up totaled, but my insurance will pay for it. The car was, of course, totaled, I came out unscathed. My insurance company dropped me the next time it came up for renewal — totaling a car is a great way to flunk an underwriting review, dontcha know.
I find myself thinking back to that, contemplating the next few weeks in Brooklyn. Omicron appears to be insanely transmissible, like sci-fi movie grade transmissible. I think I have a pretty good idea why; there are two main reasons, and they’re both really cool in a nerdy science-y way.
First, it appears to infect cells and replicate more efficiently in bronchial tissue. From the article:
A study led by researchers from the LKS Faculty of Medicine at The University of Hong Kong (HKUMed) provides the first information on how the novel Variant of Concern (VOC) of SARS-CoV-2, the Omicron SARS-CoV-2 infect human respiratory tract. The researchers found that Omicron SARS-CoV-2 infects and multiplies 70 times faster than the Delta variant and original SARS-CoV-2 in human bronchus, which may explain why Omicron may transmit faster between humans than previous variants. Their study also showed that the Omicron infection in the lung is significantly lower than the original SARS-CoV-2, which may be an indicator of lower disease severity. This research is currently under peer review for publication.
Second — and this is close to my heart, because it uses computational fluid dynamics and really cool computer modeling — it appears to last a lot longer in the air, according to a recent New York Times article. Here’s the relevant quote:
The buzzing activity Dr. Amaro and her colleagues witnessed offered clues about how viruses survive inside aerosols. The mucins, for example, did not just wander idly around the aerosol. The negatively charged mucins were attracted to the positively charged spike proteins. Charged atoms such as calcium fly around the droplet, exerting powerful forces on molecules they encounter.
Dr. Amaro speculated that the mucins act as a shield. If the virus moves too close to the surface of the aerosol, the mucins push them back in, so that they aren’t exposed to the deadly air.
“What we think is that it’s actually covering itself in these mucins, and that’s acting like a protective coating for it during flight,” Dr. Amaro said.
This discovery may help explain how the Delta variant became so widespread. Delta’s spike proteins have a more positive charge than those on earlier forms of the coronavirus. As a result, mucins huddle more closely around them. That attraction could potentially make the mucins a better shield.
Every now and then, one of the simulated coronaviruses flipped open a spike protein, surprising the scientists. “The Delta variant opens much more easily than the original strain that we had simulated,” Dr. Amaro said.
Once a coronavirus enters someone’s nose or lungs, the Delta spike’s wide opening may make it better at infecting a cell. But Dr. Amaro suspects that it’s bad for a coronavirus to open a spike protein when it’s still inside an aerosol, perhaps hours away from infecting a new host. “If it opens too soon, it could just fall apart,” Dr. Amaro said.
Some of the molecules that are abundant inside aerosols may be able to lock the spike shut for the journey, she said. Certain lung surfactants can fit into a pocket on the surface of the spike protein, preventing it from swinging open.
To test that idea and explore others, Dr. Amaro and her colleagues are stretching out the time frame of their simulation a hundred times, from ten billionths of a second to a millionth of a second. They’ll also investigate how the acidity inside an aerosol and the humidity of the air around it may change the virus.
Dr. Amaro and her colleagues are making plans to build an Omicron variant next and observe how it behaves in an aerosol. They want to wait for structural biologists to work out the three-dimensional shape of its spike proteins before getting started. But just looking at the early findings about Omicron, Dr. Amaro already sees one important feature: “It is even more positively charged,” she said.
Because Omicron’s spike proteins are even more positively charged than Delta’s, it may build a better mucin shield in aerosols. And that may help make it even more transmissible.
Now, even the original strain had an aerosol half life of about 2.7 hours. Now, imagine starting with significantly more virus that’s hardier in the air.
This requires a big rethink of who we might consider to be a “close contact.” If you live in an apartment building with shared hallways, ducts, or vents, you should consider everyone in your building — and especially your floor and your “line” — to be close contacts. In the beginning there were genuine fears that apartment buildings were going to be “vertical cruise ships.” For the most part, that didn’t turn out to be the case in the United States, but our luck has probably run out on that score. Unless your apartment is sealed tight like a submarine or a spaceship, the virus will have no trouble making its way through the cracks in your door. Aerosols are going to tend to follow a Brownian motion and eventually fill up all available indoor space uniformly. If you haven’t already rigged up an air purifier, you’re too late.
So here I am. I think I’ve got a hand I can work with; I’m quadruple vaxed (I’m not going to get into reasons or the nexus of risk factors at play for me, but the best way to explain it is that I’m in survival mode and really, truly, honey badger don’t give a shit, honey badger just takes what it wants). I’m resigned to the fact that, no matter what I do, I’m going to get it in the next couple weeks, and I’m making contingency plans accordingly. So should you. Obviously, you should get boosted if you haven’t already. Going back to the car analogy — you have a date with a guard rail, and you’d better have all the appropriate safety features ready.