The case numbers are starting to look frightening so let’s end the week on an upbeat note.

A few days ago researchers at the University of Hong Kong announced that they’d been testing the new variant on human respiratory tract tissue to see how it behaves. The bad news is that it replicates in the bronchial tubes at 70 times — no typo — the rate that Delta does. No wonder it’s suddenly everywhere. Infected people must be chimneys of viral particles with that much in their airways.

The good (actually, great) news was that Omicron replicated less efficiently than Delta in the lungs, which is where illness turns severe. That also jibes with the impressions of doctors from South Africa that cases of the variant tend to look more like the flu or a nasty cold than traditional COVID pneumonia that impairs breathing. The key bit from the Hong Kong study:

Scientists at Cambridge in the UK have been conducting a similar experiment. They devised a pseudovirus designed to mimic Omicron’s distinguishing features and then applied it to respiratory tissue, comparing what they saw it do to what Delta and the “wild type” (i.e. original Wuhan) virus did. Results: Similar. Omicron doesn’t seem to threaten the lungs the way previous versions of the virus have. The new variant is in green, Delta is in blue, and the original virus is in black:

1. Omicron Spike protein mediates deficient cell entry and is inefficiently cleaved compared to Delta spike. We tested viral entry mediated by Wild Type, Delta and Omicron spikes using a pseudotyped virus system, infecting primary 3D lung alveolar organoids. pic.twitter.com/BJ0GvySLTg

— Gupta Lab (@GuptaR_lab) December 17, 2021

2. Omicron Spike protein induces relatively poor cell-cell fusion compared to WT and Delta. We expressed spike in cells stably expressing split GFP, so that Green signal could be measured over time upon cell-cell fusion and syncitia formation. The difference is significant. pic.twitter.com/rtWFZj4yGY

— Gupta Lab (@GuptaR_lab) December 17, 2021

Gupta Lab isn’t prepared to say definitively that this proves the new variant is less of a threat to the lungs (“further work is needed”) but it’s an encouraging signal at a moment when everyone could use one. The lab also confirmed that a third dose of Pfizer does a solid job of neutralizing Omicron, something several other studies have found. The booster works. If you’re open to getting it and haven’t yet, now’s the time.

Despite the optimistic findings, though, Gupta goes on to note that “the significant growth of Omicron nevertheless represents a major public health challenge.” You know why: We’re walking into a “viral blizzard” which is destined to bury an unlucky few even if the symptoms for most are mild. If half the country catches Omicron at once, the tiny percentage who experience a severe case will still be a big load for hospitals that can’t bear the load they’re already carrying. In NYC, the looming crisis is in plain sight: “And in New York City, where testing lines have wrapped around blocks and people report wait times well over an hour, 10,286 positive cases were reported Friday. That total is up 20% from the previous day, and 100% from two days earlier. It’s also the highest reported testing day for the city since the beginning of the pandemic, and the first time the city saw more than 10,000 cases in a single day.”

If only one percent of those 10,000 end up hospitalized, that’s 100 new ER cases to come in a week or two. And at the rate the virus is doubling, we’d expect 200 new ER cases 48 hours later. And 400 two days after that.

There’s hopeful news this evening, though. Pfizer is looking ahead at and believes the pandemic might finally end by, uhhhhhh — 2024.

“We believe Covid will transition to an endemic state, potentially by 2024,” Nanette Cocero, global president of Pfizer Vaccines, said during an investor call Friday.

Covid-19 would reach the endemic level when populations have enough immunity from vaccines or from prior infections to keep transmissions, hospitalizations and deaths under control even as the virus circulates.

Isn’t Pfizer the same company that’s about to put a wonder drug on the market that should prevent severe COVID for 90 percent of the high-risk people who take it? How the hell does that not get us to endemicity before 2024?

Oh well. Just two more years to stop the spread.

Until then, the restrictions will continue until morale improves. News from Maryland this afternoon:

#BREAKING @pgcps is closing all schools Monday and going back to online learning for a while. Here are the details: pic.twitter.com/EdHvnoFgyA

— Brad Bell (@Brad7News) December 17, 2021

The CDC offered a little assurance to jittery school districts this afternoon, advising that unvaccinated students who’ve been exposed to someone with COVID don’t need to quarantine so long as they’re testing negative. Which is nice, except that practically every kid in the country is going to test positive at some point in the next month or two and have to quarantine anyway for awhile. Are schools going to stay open and let kids cycle in and out and back in as they catch COVID or are they going to foolishly shut down and wreck another year of education?

Anyway, another relentlessly sh*tty winter ahead although — probably — not as sh*tty as last year’s.