By Maria Medina

SAN JOSE (CBS SF) — On Sunday, the nation’s top doctor said he’s “worried” about the trajectory of the pandemic in the United States as the highly-transmissible Delta variant tears through the country.

“I am worried about what is to come, because we are seeing increasing cases among the unvaccinated, in particular,” said U.S. Surgeon General Dr. Vivek Murthy.

READ MORE: San Jose Police: Smash-And-Grab Thieves Target Eastridge Mall Jewelry Store; 4 Suspects Sought

According to the L.A. Times COVID-19 tracker, cases increased by 213.1% over a 14-day span. On Friday, California reported 4,651 new cases.

“We’re pretty much paralleling the United States,” said University of California Berkeley Prof. and Infectious Disease Public Health Expert Dr. John Swartzberg. “That’s disappointing because in the middle of June, California was doing much better than the rest of the United States.”

Sunday marked one full weekend after Friday’s announcement from seven Bay Area county public health officers recommending that people wear masks indoors regardless of vaccination status. Solano and Napa counties are the only counties that didn’t join the collective advisory.

But not everyone got the message about the recommendation, and some couldn’t care less.

Dave, who didn’t want to release his last name, said he’d rather not listen to one source of data when it comes to the pandemic.

READ MORE: Guard Indicted for Sexual Assault of Inmates at San Joaquin County Jail

“Why would I wear a mask indoor,” he said. “A lot of data has been published that it’s not really necessary to wear a mask at this time.”

But others, including Jenny Chung, have kept their masks on despite the Centers for Disease Control and Prevention’s guidance that those who are vaccinated do not need to wear a mask.

“Just to be safe,” said Jenny Chung who was wearing a mask outdoors while at the busy Santana Row.

“It’s pretty clear now after a year and a half of this discussion that masks work,” Swartzberg said. “I think people know that.”

In Los Angeles County, an indoor mask mandate went into effect on Saturday.

MORE NEWS: Arrest Made In Stalking, Sexual Assault Of Legally Blind Woman In Cupertino

Bay Area public health leaders said they would review the region’s case count in a few weeks before deciding what next step to take.