March 15 (UPI) -- A highly contagious COVID-19 variant could soon become the dominant strain of the coronavirus in the United States even as spring break festivities ramp up, a top health official warned Monday.
The B.1.1.7 coronavirus variant, first identified in Britain, remains on track to become the dominant variant by the end of March or early April, Centers for Disease Control and Prevention Director Dr. Rochelle Walensky said in a briefing Monday.
Although its spread is not evenly distributed across the United States, "we do have B.1.1.7 reported in 50 jurisdictions, over 4,700 cases reported so far, and that's just based on what we're evaluating and sequencing," she said.
"In some states, Florida and California, it's up to 25 percent. In other states, it's lower. Our current models still project, by the end of March, early April, B.1.1.7 will be the dominant variant."
The variant is up to 100% more deadly than the original strains of the virus, according to a study published last week by the British Medical Journal.
Researchers also found it is more contagious than earlier strains and was the primary reason for the most recent round of lockdowns across Britain. It has already been detected in more than 50 countries worldwide.
Walensky noted that the emergence of the British variant has been associated with sharp spikes in new COVID-19 cases in Europe and voiced fears that the United States could see a similar surge.
"This past Friday, we saw more travelers pass through our airports -- over 1.3 million," she said. "This is the most travelers that we've had in a single day since last March, before the WHO declared the global pandemic.
"We have seen footage of people enjoying spring break festivities maskless. This is all in the context of still 50,000 cases per day."
Walensky pleaded with Americans "for the sake of our nation's health" not to relax in their vigilance against transmission.
New COVID-19 cases, she said, "will climb now if we stop taking precautions when we continue to get more and more people vaccinated."
Also at Monday's briefing, White House healthcare advisor Andy Slavitt announced the administration is increasing the Medicare reimbursement for COVID-19 shots from about $23 per shot to $40 per shot, or $80 total for a two-dose vaccine.
"This will make it easier for more healthcare providers to get out into communities and give more COVID shots to people in need," he said.