Newly reported Covid-19 cases and deaths in the U.S. both rose from a day earlier, as public-health officials and experts warn that a recent drop in infections is showing signs of flattening. “We are at a critical nexus in the pandemic,” Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, said Wednesday, noting the seven-day averages of both new cases and deaths have increased from the prior seven days.

The possible stagnation in infections comes as more states are rolling back restrictions following a significant drop from highs reached in January. The moves have created friction. President Biden on Wednesday criticized state leaders for loosening protective measures, saying it was a “big mistake.” Meanwhile, vaccinations, which are seen as key to ending the pandemic, appear to be speeding up. More than 52.8 million Americans have received at least one shot, representing 20.7% of the adult population, according to the CDC.