Two New Year's Eve parties in New York City, one in Manhattan with more than 145 people and another in Queens with more than 300 people, were shut down by city sheriff deputies, according to a Tweet posted by the NYC Sheriff's Twitter account on Friday.

The charges in connection with the shutdowns included violating emergency orders, lacking a liquor license and health code violations.

-ABC News' Joshua Hoyos contributed to this report.

Despite repeated warnings not to travel for the holidays from the Centers for Disease Control and Prevention, 14,388,562 people passed through Transportation Security Administration (TSA) checkpoints between Dec. 18 and Dec. 31.

Still, that number pales in comparison to previous years. In 2019, 33,242,050 people were screened by the TSA at U.S. checkpoints during the same period.

-ABC News' Sam Sweeney contributed to this report.

Three new cases of the new COVID-19 variant first identified in the U.K. were reported by health officials in San Diego Thursday, leading them to believe there's community-wide transmission of the new variant in the area.

The new variant, known as B. 1.1.7., has also been detected in Colorado and Florida, and is believed to be more transmissible than the old variant, but not thought to be more deadly.

"We believe that many more cases of the B. 1.1.7. strain will be confirmed in the coming days and weeks," Dr. Eric McDonald, medical director of epidemiology and immunizations services at the country health department, said in a statement.

-ABC News' Jenna Harrison contributed to this report.

California reported 585 COVID-19 deaths over 24 hours on Friday, the highest one-day death toll that the state has reported thus far. Since some counties, such as hard-hit Los Angeles, are still confirming deaths from the virus not counted over the holidays, it's not yet known whether Friday's death report is an anomaly.

Intensive care unit capacity in the state remains extremely strained, particularly in Southern California and the San Joaquin Valley, each of which had 0% ICU capacity as of Friday, according to the California Department of Health.

-ABC News' Jenna Harrison contributed to this report.

Public Health England does not recommend mixing COVID-19 vaccines from different suppliers, according to the agency's head of immunizations, Dr. Mary Ramsay.

"We do not recommend mixing the COVID-19 vaccines -- if your first dose is the Pfizer vaccine you should not be given the AstraZeneca vaccine for your second dose and vice versa," Ramsay said in a statement Saturday. "There may be extremely rare occasions where the same vaccine is not available, or where it is not known what vaccine the patient received. Every effort should be made to give them the same vaccine, but where this is not possible it is better to give a second dose of another vaccine than not at all."

The clarification comes amid questions over the British government's updated guidance on COVID-19 vaccines, which now says that if individuals who received the first shot go to an immunization site where that same vaccine is not available for a second shot, or if the first vaccine received is unknown, "it is reasonable to offer one dose of the locally available product to complete the schedule."

"This option is preferred if the individual is likely to be at immediate high risk or is considered unlikely to attend again," the guidance adds.

The guidance, which was updated Thursday, also notes that "there is no evidence on the interchangeability of the COVID-19 vaccines although studies are underway," and thus "every effort should be made to determine which vaccine the individual received and to complete with the same vaccine."

Next week, the United Kingdom is set to begin distribution of a COVID-19 vaccine developed by England's University of Oxford and manufactured by British-Swedish pharmaceutical giant AstraZeneca, after the drug was approved Wednesday for emergency supply. Another COVID-19 vaccine developed by U.S. pharmaceutical giant Pfizer and its German partner BioNTech was approved in the U.K. on Dec. 2 and rollout began a week later.

ABC News' Zoe Magee contributed to this report.