(CNN)States are racing to get Covid-19 vaccine supplies and distribution in order as the US Centers for Disease Control and Prevention warned Friday of more contagious variants of coronavirus potentially exacerbating the spread.
States look for more Covid-19 vaccine doses as the nation's death toll nears 400,000
CDC officials implored Americans to continue with preventative measures against the coronavirus, while highlighting the variant first identified in Britain known as B.1.1.7.
The B.1.1.7 variant appears to more readily infect human cells and one CDC simulation of its transmissibility raised concerns that it could become the United States' most dominant form of coronavirus by March.
The variant has been identified in about a dozen states with Michigan being the latest state to detect a case. State health officials on Saturday identified the patient as a Washtenaw County woman who recently traveled to the UK.
The CDC has called for aggressive vaccine distribution to try to stem the tide. "Higher vaccination coverage might need to be achieved to protect the public," CDC researchers warned.
On Friday, more than 3,400 Covid-19 deaths were reported in the US, as the total death toll from the pandemic edged closer to 400,000. The nation also recorded its 11th consecutive day of more than 200,000 infections, per Johns Hopkins University data.
On Saturday, Los Angeles County became the first in the US to surpass 1 million cases -- more than Illinois' Cook County and Arizona's Maricopa County combined, according to Johns Hopkins data.
At least 12.2 million doses of Covid-19 vaccines have been administered in the US as of Friday, according to the CDC, as the federal vaccine rollout has received intense scrutiny and criticism from state officials.
Some states were upset by news from Health and Human Services Secretary Alex Azar, who said Friday there is no "reserve stockpile" of vaccines available to release.
"We now have enough confidence that our ongoing production will be quality and available to provide the second dose for people, so we're not sitting on a reserve anymore," Azar told NBC News' Lester Holt. "We've made that available to the states to order."
Asked about the apparent lack of so-called reserve shots, CNN medical analyst and emergency physician Dr. Leana Wen said, "I honestly don't understand how we got to this point, because this is right now in the world the most precious commodity."
"These are doses that were promised to the states," she said. "How are state health departments and local health departments supposed to plan vaccination campaigns when they don't know what's coming their way, or even if there is additional supply?"
"We need answers from the federal government," she added. "We need honesty and transparency."
Governors across the country are also expressing frustration about the federal government's efforts to distribute vaccines.
New York Gov. Andrew Cuomo on Saturday said the state expected to receive just 250,000 doses next week despite the fact 7 million New York residents are now eligible to receive a vaccine.
"We are in a footrace to get the vaccine into the arms of eligible New Yorkers as quickly and equitably as possible," Cuomo said in a statement. "However, we now have 7 million New Yorkers vying for a fraction of doses made available to use by the federal government."
"We need Washington to step up and increase New York's supply to make sure everyone who wants the vaccine has the opportunity to get it," he said.
Colorado Gov. Jared Polis said Friday he is "extremely disappointed that we were lied to" about the reserve vaccines, and that the next vaccines "will be delivered in the future of the supply chain."
"There is no influx of doses, contrary to a call we had with the Vice President (and) the Secretary of Health three days ago, where they informed us we would be getting an additional quantity available to the states," the governor said.
Polis estimated that of the 58,000 remaining doses in Colorado, "they will likely all or almost all be used by Sunday."
Governors from Michigan, Wisconsin and Minnesota wrote to Azar, critical of federal plans and hopeful they could purchase vaccines from manufacturers directly.
"Without additional supply or authorization to purchase directly, our states may be forced to cancel plans for public vaccination clinics in the coming weeks, which are expected to vaccinate tens of thousands. It's time for the Trump administration to do the right thing and help us end this pande