To encourage wider dissemination, we're pleased to provide here an author-abridged and -authorized version of a recent number of the Stethoscope on Rome blog by Susan Levenstein, MD. A long time resident of and practicing internist in Rome, she has been interviewed in many countries both in the US and in Europe. She here dissects the latest news, as of four days ago, on the Covid-19 omicron variant.
Dr. Levenstein, trained in the US and an avid student of its medical system, is a reader of HCR. Her own blog beautifully complements and extends what we do here. Readers would do well to subscribe to both, as well as to consider dipping into her recently published, and most illuminating ,autobiography, Dottoressa. This account of a life and career spanning two cultures is a masterful overview not just of a major component of European medicine — one of the EU's most successful systems — but of the comparative aspects of national health systems across two continents.
[Jump to succinct run-down on holiday tips — what to do and not to do: skip to the end.]
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An Update and Some Advice on Safe Celebration from Dr. Levenstein
Vaccines
Evidence that the Omicron variant escapes vaccine protection is mounting. Take the 7 young, healthy German visitors to South Africa who all fell ill with Omicron despite being triple vaccinated, perfect demonstration that neutralizing antibodies from boosters do not necessarily translate into real-life protection.
Our best data come from a UK study. Vaccine effectiveness against symptomatic Omicron, 15 or more weeks after dose 2, was nil for AstraZeneca, 35% for Pfizer. A Pfizer booster raised it to 71% following AstraZeneca, to 76% following Pfizer. Two-dose Pfizer was considerably more effective against Omicron in the short run, 88% at 2-9 weeks after dose two. Since higher doses of medications generally last longer, simply hiking up Pfizer’s 30 mg to Moderna’s 100 mg or even Moderna’s 50 mg booster might make that high effectiveness longer-lasting. That’s purely my own, possibly crazy, idea.
Another study, from a South African insurance company, found double vaccination with Pfizer 70% protective against Omicron hospitalization, but just 60% at ages 70-79. Against any COVID-19, effectiveness was only 33%. Too few South Africans have received boosters for this study to gauge their effect.
Are new vaccines or new versions of old vaccines necessary? As of December 15th Anthony Fauci was still saying no, because “Our booster vaccine regimens work against Omicron.” I say yes: even 76% protection is not good enough.
Transmissibility
Omicron is definitely a superspreader. In South Africa the most useful measure (Rt) for COVID-19 reproduction rose from 0.8 late in the Delta wave to well over 2 now. But most South Africans have some immunity from prior exposure (seropositivity rate 60-70%), so the rate of spread could be even faster elsewhere. Indeed, confirmed Omicron cases double in the UK every 3 days, for an estimated Rt of 3.7, meaning every case infects about 4 others. If anything, it’s worse in the US: 0.7% of infections 2 weeks ago, 12.6% one week ago, 73% now.
A laboratory study from Hong Kong gives early hints of why Omicron behaves as it does. Researchers exposed surgical specimens of bronchial and lung tissue to the Wuhan, Delta, and Omicron strains, then watched for 48 hours. Omicron multiplied faster than the others in bronchial cells but more slowly in the lung, perhaps explaining both sky-high transmissibility and low virulence.
Severity
In Denmark the new variant is rapidly taking over. But as of December 12th they’d had only 27 hospitalizations out of 2471 cases, compared with a Delta-wave hospitalization rate of around 10%. Danish scientists are concerned nonetheless:
- The new variant has spread thus far mostly in young people, who rarely get very sick
- COVID-19 patients often deteriorate a week or more after symptom onset, so it’s early to judge
- Denmark is the most highly vaccinated country in Europe, but most have had only two doses of vaccine, and boosting everybody will be a logistical nightmare
- The variant spreads like wildfire, so even with less severe disease, the hospitals could be overwhelmed
Currently that wildfire is burning its way through the US, where only 72% of adults have had even two doses of vaccine (versus 96% in Denmark) and where 15% of all adults – including 5% of those over 65 – have still not had a single shot.
The South African insurer’s study found a 29% lower hospitalization rate than in early 2020. And a government presentation (screenshots above) reports strikingly lower mortality and ICU admission rates among hospitalized patients than in earlier waves. Maybe doctors are hospitalizing people who are less sick, but that seems improbable. More relevant is that South Africans’ widespread previous exposure to SARS-CoV-2 and their relative youth (median age 28, versus 39 in the US) predict milder disease whatever the viral strain.
Yet more hints: 4 of those 7 young Germans in South Africa had only cold-like symptoms, but 3 became short of breath despite their age, triple-vaccination, and normal oxygen saturations. And 85 Omicron-related hospitalizations, mostly in double-vaccinated individuals, have been reported in the UK, with 7 deaths.
Predicting the future
A recent Bloomberg headline — "England could face 75,000 deaths this winter" — is terrifying. But if you look at the related study itself you see less dire results. The researchers constructed models based on different levels of vaccine efficacy and immune escape, with the 75,000-death figure assuming high immune escape and boosted vaccine efficacy of 50%-60%. But with our best estimate of boosted effectiveness over 70%, the number of hospitalizations and deaths will be lower. Even more crucially, the models assume that Omicron is just as virulent as Delta. Since considerable evidence indicates the contrary, those dire predictions should be further adjusted downward. The authors cautiously call their report not a preprint but a work in progress, to be updated as more data become available.
However… Tedros Adhanom Ghebreyesus, the non-alarmist Director-General of the WHO, emphasizes, as I do, that even if Omicron does cause milder disease it is so contagious that it could still overwhelm health care systems if huge numbers of people get sick at once. A giant surge of even mild cases could wreak havoc on economies, healthcare systems, and people’s lives, with swab-positives and their contacts staying home in isolation or quarantine. A giant pandemic of long COVID would likely ensue, since it can follow mild disease – possibly (questionably) even asymptomatic infection. In the long run Omicron should be the variant from heaven, infecting more people than Delta while causing fewer deaths, but it could sure be hell in the next few months.
What to do? It seems obvious that we need to vaccinate the unvaccinated like crazy, boost the vaccinated like crazy, work like crazy on Omicron-specific vaccines, and intensify masking, ventilation, and distancing. I personally support even more drastic measures: institute Green Passes everywhere (coming soon in the UK), close down restaurants and other public-facing businesses for several weeks (happening already in the Netherlands), promote working from home, quarantine people entering countries, or US states, from high-risk areas, and consider brief lockdowns. Time will tell.
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Some tips to make yourself safer.
- keep the guest list down, so seats can be spaced out at the table
- make sure everyone is vaccinated (with boosters if they’re five months out)
- everybody should do rapid tests that morning
- anyone with the slightest symptom should stay home
- party outdoors if weather permits
- everybody wash their hands when they come in
- leave a window at least partly open
- consider wearing masks when not actually eating or drinking
- consider investing in a portable HEPA air purifier: examples in the US and Italy
- hugs and kisses: try to resist the temptation
- separate unvaccinated kids from older adults
- no Christmas carols! (singing is the best way to spread droplets)
- be extra careful if anyone is over 65, chronically ill, immunosuppressed, or pregnant
- be extra careful if there’s high community transmission
- coming in by train, bus, or airplane? Wear KN-95 masks when travelling, grab bites quickly, open a window if you can…
- and, ideally, self-isolate for 3-5 days before the event
