CNN -- The pandemic's end is in sight -- but right now, the US is in a critical spot.
A highly contagious -- and potentially more deadly -- coronavirus variant is spreading across the US, threatening to send infection numbers spiking once again. Meanwhile, the number of vaccines administered across the country is growing, as officials work to get as many shots into arms as possible in hopes of soon being able to suppress the spread of the virus.
It's a "neck and neck" race between the two, one expert says.
"This is crunch time," Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine, told CNN on Saturday. "This is going to be our most difficult period right now in terms of seeing who wins out."
With less than a quarter of all Americans having received at least one dose of a Covid-19 vaccine -- and only about 13% fully vaccinated -- doubling down on safety measures now is what could help curb another surge, experts have repeatedly stressed.
"If we can hang on another month, another six weeks, that's going to make a huge difference," Hotez added.
Instead, air travel is hitting pandemic-era records, with TSA screening more than 1.4 million people at airports Friday -- the biggest day for air travel more than a year.
Spring break crowds are swelling, with Miami Beach officials declaring a state of emergency Saturday in response to crowds the mayor says have been "more than we can handle."
Michigan cases and hospitalizations climbing
In Michigan, where the governor announced a series of eased restrictions earlier this month, officials now say the state could potentially be at the start of another surge.
"Our progress with Covid-19 is fragile," Dr. Joneigh Khaldun, the chief medical executive for the state of Michigan, said in a news conference Friday. "While we're making great progress with our vaccination efforts and many people are doing the right thing by wearing masks and not gathering in large groups, what we are seeing now is very concerning data that shows that we are going in the wrong direction."
Case rates have been increasing for the past month, Khaldun said, and increased 77% since mid-February.
The state's percent of Covid-19 tests that are positive have also jumped 177% since mid-February, Khaldun said. And hospitalization rates have also been climbing for the past two weeks, Khaldun added.
Michigan has also reported the country's second-highest number of cases of the B.1.1.7 variant, after Florida, according to CDC data.
"It's immensely concerning," Dr. Rob Davidson, an emergency room physician in the state, told CNN Saturday. "We know in the past, cases went up, then hospitalizations, then deaths followed."
Davidson told CNN he's even more worried now that variants are circulating, and hopes the state can make enough headway to protect residents.
"It remains to be seen," Davidson said. "We just would rather not wait and find out. We'd rather get people to mask up, keep distancing and get those numbers down."
'A growing threat in our country'
There are several dangerous variants that have experts concerned.
The Centers for Disease Control and Prevention has estimated it will become the dominant variant of the virus in the US by the end of this month or early April.
The B.1.1.7 variant "likely accounts now for about 20 to 30% of the infections in this country and that number is growing," Dr. Anthony Fauci said during a White House briefing Friday.
It's more contagious and could cause more severe disease, Fauci added. Recent research also suggests the variant may also be associated with a higher risk of dying from Covid-19.
The good news: vaccines appear to protect well against the variant, Fauci said, and treatments like monoclonal antibodies also appear to work against it.
"The way we can counter 1.1.7, which is a growing threat in our country, is to do two things: to get as many people vaccinated as quickly and as expeditiously as possible with a vaccine that we know works against this variant. And finally, to implement the public health measures that we talk about all the time," Fauci said.
"Masking, physical distancing, and avoiding congregate settings, particularly indoors," he added.
More than 43 million Americans fully vaccinated
So far, more than 79 million Americans have received at least one dose of a Covid-19 vaccine, according to CDC data, and more than 43 million are fully vaccinated.
The growing numbers are encouraging, but experts say the country still has a long way to go to reach the levels needed to suppress spread of the virus -- and must address the vaccine hesitancy as well as political divisions that stand in the way.
In Missouri, Gov. Mike Parson said Friday that while he encouraged everyone to get vaccinated and thinks it's the right thing to do, he knows there will be a "certain amount of people" who are not going to take the vaccine, "and they have every right to do that."
"We got to do a better job of making sure everybody understands the importance of the vaccine, and yet maintain the respect of people that don't want to take a vaccine, and it is going to be a challenge to see how many people we can get done, but we're going to do everything we can," the governor said.
A recent CNN poll conducted by SSRS, showed that while 92% of Democrats say they have gotten a dose of the vaccine or plan to get one, that falls to 50% among Republicans. In Georgia, Gov. Brian Kemp said earlier this month officials across the state are working with local organizations, like local churches and civic clubs, to tackle vaccine hesitancy -- including among White Republicans.
To get more shots into arms faster, many state leaders have also extended eligibility guidelines, with some already setting a date for when all requirements will be lifted.