The head of the CDC says the US could face a COVID-19 surge after more than 1.3 million Americans traveled around spring break

• The head of the CDC warned of a COVID-19 surge over spring break.
• The US had more air travelers Friday than on any other day in the past year.
• "All in the context of still 50,000 cases per day," Dr. Rochelle Walensky said.

The head of the Centers for Disease Control and Prevention said she was "pleading for the sake of the nation's health" after more than 1.3 million Americans traveled by air on Friday, the most during the coronavirus pandemic.

"This is all in the context of still 50,000 cases per day," Dr. Rochelle Walensky, the CDC director, said at a press briefing Monday.

Some Americans enjoyed their spring break "maskless," she said.

Her comments came after the Transportation Security Administration recorded more than 1.3 million Americans going through airport security screening on Friday.

The average number of daily new coronavirus cases reported in the US fell below 50,000 last week for the first time since October. The current figure is more than 53,000, according to data from Johns Hopkins University.

Walensky said the US was just starting "to turn a corner," with the data moving in the "right direction." She said the path forward depended on what people did to protect themselves and others, including following public-health precautions and getting a vaccine when offered.

"I'm pleading with you for the sake of our nation's health. These should be warning signs for all of us," Walensky said.

"Cases climbed last spring. They climbed again in the summer. They will climb now if we stop taking precautions."

The US has recorded more than 29 million coronavirus cases overall and more than 535,000 deaths, per Johns Hopkins.