British health authorities reported 41,385 new COVID-19 cases Monday, the highest daily rise since the pandemic began. Over the last seven days, 256,220 people tested positive, which is a 25.7% increase in positive tests since the week prior.

England's Chief Scientific Adviser Patrick Vallance said last week that the newly identified U.K. variant is more dominant and significantly more transmissible than the old coronavirus variant.

There’s no evidence the new variants are more deadly and it’s highly likely the vaccine will still work, experts said at a virtual Q&A hosted by the World Health Organization last week.

In total, the U.K. has reported 2,329,730 infections and 71,109 deaths from the virus.

-ABC News' Christine Theodorou contributed to this report.

One out of 17 Americans, a total of 19 million people, have tested positive for coronavirus, according to data from Johns Hopkins University. One in 1,000 have died from the virus.

Since some states don't report and others give incomplete updates over the holidays, last week's data doesn't provide an up-to-date picture of the U.S. outbreak. But even without those numbers, December's forecast remains grim, according to an ABC News analysis of data from The COVID Tracking Project.

Since Dec. 1, there has not been a single day with less than 1,000 COVID-19 related deaths reported, the data showed.

The United States logged more than 5.4 million COVID-19 cases in December, more than any month on record and roughly equivalent to 70 Americans testing positive for the virus every 30 seconds.

-ABC News' Arielle Mitropoulos contributed to this report.

New Jersey vaccinated its first nursing home resident, a 103-year-old resident of Roosevelt Care Center in Old Bridge Monday.

Mildred Clements, a Newark native who has lived through two pandemics, was met by a round of applause from the governor and state health commissioner after receiving her shot. Residents and staff at roughly 90 long-term care facilities in New Jersey are slated to start vaccinations Monday, according to the governor's office.

-ABC News' Aaron Katersky contributed to this report.

The Transportation Security Administration (TSA) on Sunday saw the highest number of people screened at the airport since the pandemic hit, a spokesperson tweeted Monday.

The 1,284,599 people screened at airports nationwide marks the sixth day in the last 10 with more than 1 million airline screenings. "If you choose to travel, please wear a mask," Lisa Farbstein, the TSA spokesperson, wrote on Twitter.

-ABC News' Michael Kreisel contributed to this report.

A staggering 299,087 new cases of COVID-19 were confirmed in the United States on Saturday, according to a real-time count kept by Johns Hopkins University.

It's the highest tally of newly diagnosed COVID-19 infections that a country has recorded in a 24-hour reporting period since the start of the pandemic.

An additional 2,398 deaths from COVID-19 were also registered nationwide on Saturday, down from a peak of 3,750 on Dec. 30, according to Johns Hopkins data.

COVID-19 data may be skewed due to possible lags in reporting over the holidays followed by a potentially very large backlog.

A total of 20,430,088 people in the U.S. have been diagnosed with COVID-19 since the pandemic began, and at least 350,214 of them have died, according to Johns Hopkins data. The cases include people from all 50 U.S. states, Washington, D.C., and other U.S. territories as well as repatriated citizens.

Much of the country was under lockdown by the end of March as the first wave of pandemic hit. By May 20, all U.S. states had begun lifting stay-at-home orders and other restrictions put in place to curb the spread of the novel coronavirus. The day-to-day increase in the country's cases then hovered around 20,000 for a couple of weeks before shooting back up over the summer.

The numbers lingered around 40,000 to 50,000 from mid-August through early October before surging again to record levels, crossing 100,000 for the first time on Nov. 4 and reaching 200,000 for the first time on Nov. 27.