Déjà vu.

That's what we felt when news broke about a new coronavirus variant, named omicron, being designated as a "variant of concern." It's been nearly two years since Covid-19 was declared a global pandemic, and we're yet again wondering what the future holds.

Once again, there are no clear answers. But we do know enough to begin mapping out the space of possibilities.

We know enough to ask, as we have at past moments in the pandemic: What are the (relatively) "good," "bad," and "ugly" scenarios? 

Full disclosure: Even in the day it took us to draft this post, we've had to rethink our beliefs in light of emerging information. Still, even if these predictions are shaky, we believe there's value in reflecting on the futures that could arise—and how health care stakeholders can prepare for each one.

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The (relatively) 'good' scenario: Our existing vaccines and treatments still work, and omicron doesn't cause worse disease.

It would be misguided to label any outcome as truly "good" in a pandemic that has already killed more than 775,000 Americans and more than 5 million people worldwide.

Still, some possible futures are clearly better than others—and the best-case scenarios are those in which the omicron variant doesn't fundamentally change the course of the pandemic.

America has already given 74% of people aged 5+ at least one vaccine dose. If those vaccines are as effective against omicron as other variants, that will be a promising sign for the pandemic's future.

It's even possible that omicron's emergence could drive increased vaccine and booster uptake, as happened in the initial weeks of the delta surge. It could even advance efforts to vaccinate the world, a task that President Biden deemed a "moral obligation" in his early remarks on the omicron variant.

So how likely are current vaccines to work against the omicron variant? One reason for optimism is that most early cases and hospitalizations in South Africa appear to have occurred in unvaccinated individuals. Another is that vaccines have worked well against all past variants, including delta. Still, experts caution that omicron carries more mutations than past variants, and many of those mutations exist in areas associated in lab experiments with immune escape. In the coming weeks, we'll have more data on whether the vaccines protect against the variant.

Another "good" possibility would that omicron doesn't make people as sick as other variants (or, put more formally, that it's not especially virulent). Here, too, there's reason for optimism. Early reports out of South Africa indicate that most infected individuals have suffered only minor or asymptomatic illnesses.

But there's also reason for caution: Because the variant has emerged so recently, it's possible that most cases simply haven't had time to progress to hospitalization and death. According to WHO, there's simply no evidence to suggest that omicron's symptoms are any better or worse than those caused by past variants.

On the whole, we think a relatively good scenario remains plausible, especially in highly vaccinated regions. Additionally, our current preparedness measures—like increased testing and vaccinations, as well as even renewed calls from Dr. Francis Collins from the NIH for mask wearing indoors—may help us get ahead of omicron's spread, at least in the U.S. But there's also a risk that things will turn worse.

The 'bad' scenario: Omicron is highly transmissible and slightly more virulent than previous variants, but existing vaccines and treatments still work well.

In the "bad" scenario, the omicron variant's course could look very similar to that taken by the delta variant in the summer. It could rapidly spread throughout the nation and world, with the most severe impacts on unvaccinated populations.

Transmissibility could be a key factor in this scenario, and data on the variant's basic reproduction ratio (R₀) a metric used to describe the contagiousness or transmissibility of infectious agents, will help us further understand potential impact. The original coronavirus had a R₀ of 2.79, and the delta variant had a R₀ of 5.08. If the omicron variant's R₀ exceeds this number (and is more virulent), we may find ourselves in a "bad" scenario. Experts have speculated that omicron is likely highly transmissible since it carries mutations found on the very contagious delta variant, as well as other mutations hypothesized to increase transmissibility. The variant's apparently rapid rise in South Africa also suggests it spreads easily, although experts warn we don't yet know for sure.

If omicron turns out to be the most transmissible variant yet, we should expect another wave of cases among the unvaccinated, likely accompanied by an increase in breakthrough infections. However, so long as our vaccines still are effective, most breakthrough infections will be mild, as was the case during the delta surge.

Even in this "bad" scenario, we're still much better off than in past coronavirus waves. In just the last several weeks, we've seen the emergence of new, promising treatments—notably, oral antivirals that reduce the risk of hospitalization and severe illness. Pfizer's antiviral, Paxlovid, was shown to provide an 89% risk reduction in outpatients. Merck's antiviral, molnupiravir, was recently shown to reduce the risk of hospitalization and death from Covid-19 by 30%.

Because of the way these treatments work in the body, experts feel confident they'll remain effective against the omicron variant. It's possible that, at least at first, they could be reserved for unvaccinated people or high-risk groups or sent to areas with the greatest prevalence of the variant. It's likely that FDA will discuss these possibilities as it reviews these drugs' applications for emergency use authorization. It will also be essential that we can overcome some of the big obstacles for anti-viral treatments, such as access, rapid testing, and sufficient tracking.

Still, while post-exposure drugs will play an important role in a "bad" scenario, the key to preventing a truly "ugly" outcome will be vaccines. The World Health Organization and the Biden administration both echoed this message, recently urging people to get vaccinated and boosted to prevent further spread. Additionally, CDC just strengthened its booster recommendations, saying all eligible adults "should" get boosted (where previous guidance said they "may" get boosted) and Pfizer announced it is seeking approval of boosters for people ages 16 and 17.

The sooner vaccines are distributed throughout America and the world, the better the outcome will be—at least so long as the vaccines themselves remain effective.

The 'ugly' scenario: Vaccines falter, and omicron's virulence is dangerously high.

The biggest question, then, is: What happens if our current vaccines falter?

Here's where we want to be cautious. Most experts say omicron is extremely unlikely to fully evade existing vaccines. Scott Gottlieb, former FDA commissioner, recently said that "… if you talk to people in vaccine circles… they have a pretty good degree of confidence that a booster vaccine so three full doses of vaccine is going to be fairly protective against this new variant." It would be irresponsible, and unhelpful, for us to speculate—in absence of any evidence, and against scientists' best predictions—that vaccines could simply stop working.

But it's possible that omicron will show a degree of immune escape.

If so, then many people who are vaccinated could fall ill. They in turn could pass the virus to others. And if omicron proves to be as virulent as or worse than past variants, many of those infected—especially those who are unvaccinated—will suffer and die.

This would render the next 100 days truly "ugly," as manufacturers race to develop new vaccines and boosters against the new variant, and an already exhausted health care system copes with yet another devastating wave of cases.

In this scenario, health care leaders, policymakers, and public health officials will need to re-evaluate preventive strategies. We could once again see draconian measures such as lockdowns and sustained capacity mandates. However, President Biden recently announced that the U.S. will not resort to lockdowns or shutdowns as a result of omicron, making this possibility unlikely.

Even this scary scenario wouldn't quite bring us back to March 2020. We know dramatically more than we did then about how to detect, contain, and treat Covid-19, and manufacturers stand ready to adapt their vaccines with all due haste.

But this scenario would be horrific, and the next few months would feel all too much like déjà vu.

Parting thoughts

When we've written these predictions about the pandemic in the past, we struggled to see how our individual actions could meaningfully inflect our trajectory toward a good, bad, or ugly outcome.

But whether one or none of these scenarios play out, it is important to step back and consider how we can rely on lessons we've learned over the past two years. Lessons such as encouraging vaccine uptake by going into the community, combatting structural inequities by acknowledging and acting, helping out vulnerable countries around the world, supporting the health care workforce, and much more.

If you are feeling overwhelmed after reading through these various scenarios, stuck in the treacherous mental waters of the unknown, you are not alone. It is okay to acknowledge the confusion of constantly emerging data as we learn how to proceed. But this is also true: these unknowns will not be the end of us. Somehow, amid the chaos of constant pandemic updates and new death tolls, we continue to move forward as a collective—doing our best to stay prepared, protected, and proactive.

And for us, that is a reason for hope.

Thomas Seay contributed to this piece.