Six crucial lessons from Omicron.
What we learned in the last wave can help us survive the next one.
The Omicron variant did not take the United States by surprise. We had weeks of warning between when it was discovered in South Africa in November, and when it became the dominant cause of Covid-19 here by mid-to-late December.
What did we do in that time to prepare? Very little, other than wishful thinking. By the time Omicron cases took off here, it was too late. The horse had left the barn. The outcome, culminating in thousands of deaths per day, at some point became inevitable.
Are we consigned to a similar fate with each new variant? No. That is, if we choose to have learned anything from both the Omicron and Delta waves. Here are 6 key insights from the Omicron and Delta waves that can help us do better in the next surge.
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1. Local conditions matter. Omicron caused comparatively fewer deaths in South Africa than here, likely reflecting more immunity within the population and better weather (Omicron broke out during late Spring there). We can’t shrug off outbreaks in far flung places that are unlikely to resemble what we might experience.
2. Our surveillance tools work, if we use them correctly. We now have meaningful warnings of ensuing waves, warnings which can indicate the need to increase mitigation measures. Think how far we have come. At first, in 2020, we had to wait until people were sick enough to require hospitalization to know when Covid-19 had taken hold locally. By 2021, we were better, identifying individual cases in the community via extensive testing. But that wasn’t enough; slow results and unequal access meant unacceptable lags and missed cases. In 2022 and beyond, we can and must rely on wastewater testing to detect coronavirus outbreaks early. We should not wait for individual cases to spike to respond to outbreaks. The sooner we act, the less we must do, for less time.
3. The hospital circuit breaker concept, which I wrote about extensively here in Inside Medicine can work to keep hospitals safe. The circuit breaker dashboard my team developed to alert hospitals that their safe capacity was in danger of being exceeded performed well during Omicron. We’re now studying this, but recently my team assessed how our dashboard performed in Arizona (a hard-hit region) during the fall and early winter. Of the 40 days which we believe hospital capacity exceeded 100% since September, our dashboard had provided advance notice for 38 of them, with an average advanced notice of 10 days. (We know why we missed the other two, but I won’t spoil that now!) That means that hospitals can make adjustments (e.g. increasing staff, opening extra units, cancelling elective procedures, etc.) needed to keep them safe.
4. Small changes in behavior matter. We’re also just beginning to study this, but it appears that places like Denver, where indoor dining decreased by about 30% from its pre-Omicron levels, did better than places like San Antonio and Scottsdale, Arizona, where indoor dining actually increased during the surge. This implies that in places with people less willing to make behavioral changes spontaneously, responsible governments can implement modest changes like decreasing indoor capacity by 25%, say, rather than shutting all restaurants down completely. These actions don’t prevent cases in the long run, but they flatten the epidemic curve enough to keep adequate hospital beds open when things get tight. (If the national 2020 shutdown in the US achieved anything, it was precisely this. The fact that we failed to keep many hospitals safe during the Omicron wave is a stain on our record, especially given the tools we now have).
5. Rapid testing works and can slow down the spread of disease. In fact, a new study on rapid tests used during the Omicron wave published by the Centers for Disease Control and Prevention itself suggests that CDC’s own isolation guideline (unveiled in December) was likely too aggressive. Many with Covid-19 remained contagious longer than the CDC had assumed in their guidance. In future waves, rapid tests can be used to customize isolation periods, allowing those who are no longer contagious to resume to normal life sooner (“test to return”), while alerting those who remain contagious that they need to stay home a bit longer. This will be especially important in future waves in which we won’t yet know how long people shed contagious virus for, which is something that can change with a particular variant, depend on whether a person has existing immunity, and other factors. The Biden Administration finally heeded calls (like the one right here in Inside Medicine) to get rapid tests delivered to residences for free, but it happened later than it should have.
This final lesson from Omicron may be a surprise coming from me. Hopefully that means it’ll be more impactful.
6. We can, in part, boost our way out of surges. This goes against conventional wisdom, so let me make the case. First, 3rd doses are essential for all people over age 50, and some other high-risk individuals, and should be given as soon as an individual becomes eligible. (We also know that 4th doses are needed for the profoundly immune-compromised). For these groups, 3rd and 4th doses should not be thought of as boosters. But for people under age 40, (and maybe 50), it’s increasingly clear that 3rd doses decrease infections temporarily (i.e. delay them), but do not add protection against severe disease and other long-term consequences. That’s because, despite messaging to the contrary, the 2-dose series turns out to be extremely effective in preventing these outcomes in virtually all young adults. That means boosting younger adults constitutes, in essence, temporary prophylaxis, but is not a way to further improve outcomes among infected people (note: this might be changing for some age groups). When the CDC went with “boosters for all” last fall, it made a mistake of thinking that boosters would add sustainable protection. In fact, we already knew this was unlikely, because Israeli scientists had already quietly detected this. But another finding that seems to have been buried is how fast the boosters appeared to work in the Israel data. While some of this was behavioral changes, some was real.
We can, in part, boost our way out of surges. This goes against conventional wisdom...
To me, this all indicated that waiting to boost young people until a surge hit might be the wiser move (assuming low rates of serious adverse events occurred with the 3rd dose among the young, which is something we did not know when the booster rollout began, but thankfully basically turned out to be the case). If the booster decreases infection for 4 months, but that effect kicks in within a week, why not boost young people (like healthcare workers) right when a new concerning variant is detected. After all, variant waves seem to last 8-12 weeks. We’d be better off a little under-boosted in the first week in exchange for a more protected workforce 1-3 weeks later. People who sprinted to get boosted in September likely had little-to-no added protection against infection for most of the Omicron wave. We would have had more healthcare workers effectively boosted if we’d waited to boost us all until December 1st.
Anecdotally, I think boosters made people over-confident. Many of my boosted healthcare colleagues got Omicron, while some of us who were holdouts did not. I also find it rather troubling that my own hospital required me to get boosted by March 1st (I finally got mine in early February). What good does a booster that decreases my chance of an infection by, say, 50% for a few months do me (or anyone) if cases are 5% of their January peak? It’s a waste. They should be prohibiting us from wasting our opportunity to boost when cases are so low, so that if there’s an unexpected surge in the spring from some new as-yet-discovered variant, I can get short-term added protected from infection by boosting then, and not get sidelined as so many of my colleagues were during Omicron because their booster had already worn off. So, for a future foe like Omicron, boosters might make a great deal of sense for younger populations who need to temporarily avoid an infection--but, only if they are deployed at the right time.
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I’m often asked what the future will bring. I rarely make predictions. But given how prevalent SARS-CoV-2 remains, one thing seems likely: more variants will test us. Each time, we can perform better than the last time. Will we?
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