Recent data about the spread of COVID-19 in the U.S. is extremely concerning, the leader of the Centers for Disease Control and Prevention warned Monday.

“Please hear me clearly: At this level of cases with variants spreading, we stand to completely lose the hard-earned ground we have gained,” Dr. Rochelle Walensky said at the White House COVID-19 Response Team briefing, referencing emerging strains of the coronavirus that appear to be more transmissible, deadlier and more resistant to vaccines.

Recent declines in cases have leveled off at nearly 70,000 new cases per day, with nearly 2,000 deaths. Those number are both up 2% from the previous seven days, she said. 

“I remain deeply concerned about a potential shift in the trajectory of the pandemic,” Walensky said.

Vaccine rollout is picking up, but we still have a long way to go, she said, noting that states with aggressive reopening plans pose a serious risk to safety.

“With these new statistics, I am really worried about reports that more states are rolling back the exact public health measures we have recommended to protect people from COVID-19,” Walensky said. “I understand the temptation to do this; 70,000 cases a day seems good compared to where we were just a few months ago. But we cannot be resigned to 70,000 cases a day, 2000 daily deaths.”

However, governors across the country have begun to loosen pandemic safety rules.

In South Carolina, which is just emerging from its surge in cases, Gov. Henry McMaster (R) announced last week that people in the state would no longer need to get approval to hold events with 250 people or more.

The attitude around reopening tends to fall along party lines, with Republican governors being more eager to relax restrictions, but some Democratic leaders are also moving in that direction. New York Gov. Andrew Cuomo (D) has moved to allow indoor dining, large stadiums and arenas, movie theaters and wedding venues to resume operating with reduced capacity. 

Walensky isn’t the only one sounding the alarm on the possibility of another wave. Dr. Anthony Fauci, President Joe Biden’s chief medical adviser, made a similar warning Sunday.

“Right now, as we’re going down and plateauing, is not the time to declare victory, because we’re not victorious yet,” Fauci said on CBS News.