In the past week, a new picture has emerged in COVID-19 data: The pandemic seems to be receding from its high-water mark in the United States. The most dependable metric of COVID-19’s spread—the number of people currently in the hospital with the disease—is in its first sustained, week-over-week decline since September, according to the COVID Tracking Project at The Atlantic. Hospitalizations fell in the past week in every state but Vermont.
The number of people diagnosed with COVID-19 is falling too. New cases declined in every region of the country last week. Cases even seem to be ebbing in the coronavirus epicenters of California and Arizona, though the Sun Belt remains a hot spot. In the past two weeks, only two states—New York and Virginia—have set a single-day record for new cases. (In contrast, 13states set a new record three weeks ago.)
In other words, the numbers are finally moving in the right direction. But while the trajectoryof the pandemicis encouraging, the overall level of infectionis staggering.
“We are entering what may well be the toughest and deadliest period of the virus,” President Joe Biden declared in his inaugural address. The same day, the United States reported that 4,409 people had died of COVID-19, the highest toll of any day so far Hospitalizations might be falling nationwide, but they remain twice as high today as they were at the peak of the previous two surges. In the South, new cases have fallen from their peak, but they are more numerous today than they were when the month began; in the Northeast and West, new cases exceed their level on December 1.
The most crucial question for Biden—and for the country—is how long the overall decline can endure.
Biden has described the task at hand as a “wartime” effort against the pandemic, but the success of his cause will rest on factors partially out of his control. The Biden administration is now running a race of vaccination versus variantsit must continue to suppress transmission, and vaccinate people, before more transmissible variants of the virus emerge. The winner of this race will depend on three unknowns: mitigation, evolution, and vaccine distribution.
Since the pandemic began, two trends have defined the virus’s behavior. First, when cases and hospitalizations start to fall in a region, they continue on that path for some time. Second, when a community has a high level of ongoing infection—when the virus is simmering in the background but not yet boiling over and overwhelming hospitals—a new surge will soon start up again. Today, several key metrics are in decline, but overall community transmission remains at high levels.
Those high levels of ongoing infection make the standard tools of mitigation—social distancing, masks, and work-from-home orders—even more important to avoid continued deaths. Yet the allure of vaccination is beginning to stymie mitigation policy in some places. In Arizona, for instance, Governor Doug Ducey has opposed implementing any new mitigation efforts, because vaccinations are imminent—even though only about six doses have been administered for every 100 Arizonans, according to Bloomberg
“The vaccine is the only solution. It is the first solution that has presented itself since January 27 [of last year], when we saw the first case,” Ducey, a Republican, has said.
Ducey is not alone in resisting mitigation efforts; local leaders from both parties are loosening some of restrictions they implemented at the peak of the winter surge. Chicago, Baltimore, and Washington, D.C., have resumed some indoor dining, or are planning to resume it soon, as has the state of Michigan. Yet the virus has not been eradicated from those areas. In the District of Columbia, hospitalizations are below their peak, but still significantly higher today than they were at any point over the summer.
At the same time, the coronavirus is mutating in predictable but alarming ways. As my colleague Sarah Zhang has written, the virus has developed more infectious variants in several different places around the world. The variant that emerged in the United Kingdom may be more than 50 percent more transmissible than the coronavirus strain that dominates in the U.S. (British Prime Minister Boris Johnson claimed on Friday that the same strain may also be 30 percent more lethal.) So far, these variants seem to respond to the vaccine, but without widespread mitigation efforts, the risk increases that the virus will develop even more transmissible and lethal variants. The most immediate risk is that these new variants cause another surge of infection, and death, before mass vaccination can increase the number of Americans with protective immunity.
How likely is such a scenario? The highly contagious U.K. strain is already circulating in the U.S.: Epidemiologists have found it in at least 20 states, in many cases in Americans who have not recently traveled abroad. But that may be the least of our issues. The U.S. may have its own highly contagious strains, but we would not necessarily know about them. Infectious-disease researchers detect new variants of a virus by sequencing its genetic code as collected from hundreds of COVID-19 patients. And the CDC is only now beginning to surveil widely enough to identify new variants. One particular strain of the virus seems to have become prevalent in Southern California, but it is unclear whether this strain is more transmissible or just happened to infect more people in several unlucky super-spreading events.
Earlier this month, a CDC study suggested that if the U.K. strain is the only more transmissible variant circulating nationwide, the U.S. should not expect to see a bump in cases until the spring—at which point more than 67 million of the most vulnerable Americans should be vaccinated, if Biden’s plan bears out. Yet these models, again, account only for the U.K. variant: If a separate, “California” strain exists and is already widespread, it may cause another surge before the vaccines can suppress transmission.
Many days, the U.S. is already at or near the goal of delivering 1 million vaccine doses every day. More supply should come online soon. Potentially as soon as this week, Johnson & Johnson could deliver the results of its Phase 3 trials. The company aims to deliver 100 million vaccine doses by the spring.
Not all of the news is so rosy. Pfizer has begun reducing the number of vaccine vials it sends to the U.S., after some pharmacists found an “extra dose” in some of the vials, The New York Times reported. Because Pfizer’s contract specifies that it will deliver a certain number of doses to the U.S., the company informed the Trump administration that it would deliver fewer vials than initially promised, according to the Times. But only some types of syringes are able to use that extra dose, so Pfizer’s legalistic move may effectively reduce the number of doses available to Americans.
The U.S.’s vaccine supply, in other words, is uneven at the moment, although the Biden administration has vowed to invoke the Defense Production Act to strengthen the supply and distribution operation. The country may very well soon have tens of millions of doses on hand each week, allowing the number of Americans with immunity to outpace the growth of more contagious virus variants. Or the U.S. could find itself with another surge in cases and no near-term increase in its supply of vaccines.