Colorado’s unprecedented fall coronavirus surge has leveled off into a “high plateau,” state health officials said Thursday, as both hospitalizations and raw case numbers have stabilized in recent weeks.

The news is welcome, if still cautious. Thursday marks two weeks since Thanksgiving, which is the incubation period for the virus and is considered the window needed to wait before gauging the effects of events on spread. Officials said at a press conference that data could again climb and that even the current apparent plateau is still higher than any other peak from the pandemic thus far.

The decline and then stabilization appears to have begun after the state changed its metrics, avoiding a shutdown for many counties while instituting other, less severe restrictions. 

Rachel Herlihy, the state’s epidemiologist, said that one of two things may be happening. The first is that it may still be too early to appropriately gauge the effects of Thanksgiving and that those numbers could still bounce back up in the coming days. The other possibility is that the mitigation efforts instituted by the state and individual counties have been effective.

It’s still to soon to know which is at play, she said. But if numbers continue to stabilize or decrease, the latter “is the most likely scenario.” While deaths remain a concern, officials said mortality may decrease if numbers stay stable or continue to decline. Still, they said that they’re anticipating as many as 2,000 more deaths this month; as of Thursday morning, more than 2,900 people have died in Colorado from the virus.

Some of the stabilization and decline also roughly matches up with school districts moving their students fully online. John Douglas, the executive director of the Tri-County Health Department, said it was “hard to tease out” if closing schools had impact on numbers improving. But he did say that there have been “really low” levels of in-school transmission of the virus.

Officials have said for months that rampant community transmission will then necessarily infect teachers and students, which then cause disruption within the school. What happens in school, then, is more of a reflection of what’s happening in the community, rather than the inverse.

The news comes as the state prepares to begin doling out the first batches of vaccine shipments, which Dr. Eric France, the chief medical officer of the state Department of Public Health and Environment, said could be arriving as soon as early next week. He said that the Food and Drug Administration was meeting Thursday to discuss the Pfizer vaccine; emergency approval of the inoculation is expected very soon after that meeting concludes.

France noted two side effects present in very few vaccine recipients. One is Bell’s Palsy, which can cause muscle weakness in the face. A tiny minority of people in vaccine trials experienced with the condition. France said Bell’s Palsy is common in viral infections overall and that the FDA committee will be looking at that side effects. He also noted that in the United Kingdom, which has already started distributing the vaccine, some people with pre-existing and severe allergies, particularly to other medications, have had reactions to the vaccine, as well. But he said people with mild allergies have not been affected similarly. 

A reporter asked France about another common side effects: fevers. As health care workers are at the front of the line for vaccines, some workers then may come down with a fever, which could then exacerbate staffing issues. France said that hospitals are “having discussions about what this might mean.”