(CNN)More Americans say they are confident about getting a Covid-19 vaccine, but supplies are limited and new variants are raising concerns across the country.
A Gallup poll released Wednesday found 71% of those surveyed are willing to get vaccinated, up from 65% in late December and the highest number since July. So far, about 10% -- almost 33.8 million Americans -- have received at least one dose of the two-part vaccines, according to the US Centers for Disease Control and Prevention. About 10.5 million people have been fully vaccinated.
And while US and state leaders are optimistic vaccinations will ramp up in coming months, challenges remain, including supply shortages and equal access. Public health experts also say the US is in a race against time as Covid-19 variants spread across the country.
Cuomo says New York arenas can open
New York Gov. Andrew Cuomo announced Wednesday that arenas in the state can reopen February 23 with approval from the state's Department of Health.
This applies to any large stadium or arena, whether it's a hockey, baseball, football, soccer, or music venue, Cuomo said.
There is a 10% capacity limit for venues with 10,000 or more seats, and all attendees will need to provide a negative PCR test. They'll have to wear masks, observe social distancing and sit in assigned seats.
White House Covid-19 response coordinator Jeff Zients, along with Cuomo, also announced that two mass vaccination centers are to open in Queens and Brooklyn.
"We're meeting communities where they are in places they know and trust," said Zients. "We look forward to continuing to build on these partnerships with states and localities to scale innovative models that meet the needs of the communities we serve."
In Texas, three new major community vaccination centers will open in Dallas, Arlington and Houston, Zients announced.
And Arizona is getting a third state-sponsored vaccination site slated to serve 6,000 people per day, Gov. Doug Ducey announced Wednesday.
"The demand for vaccine doses is high, and Arizonans have made it clear they want it. We are working hard to secure more doses from the federal government and partner with private and public organizations to get the vaccine out and protect Arizonans," Ducey said.
But in Los Angeles, five vaccination sites, including Dodger Stadium, one of the nation's largest sites, will close temporarily Friday and Saturday because of a lack of vaccine, Mayor Eric Garcetti said at a news conference.
"We're vaccinating people faster than new vials are arriving here in Los Angeles and I'm very concerned," he said. "Our vaccine supply is uneven, it's unpredictable, and too often, inequitable."
Tuesday, the Biden administration said it was boosting the weekly vaccine supply going to states, tribes and territories to 11 million doses, and said it is continuing to work with manufacturers to increase supply.
CDC's new guidance on quarantine and second shots
The CDC had some good news Wednesday for the some 10.5 million Americans who have had two doses of the Pfizer/BioNTech or Moderna vaccine, and are fully vaccinated: They no longer have to quarantine after being exposed to someone with Covid-19.
"Vaccinated persons with an exposure to someone with suspected or confirmed COVID-19 are not required to quarantine if they meet all of the following criteria," the CDC added.
The criteria are they must be fully vaccinated and at least two weeks have passed since the second shot, because it takes two weeks to build full immunity.
The CDC also released guidance Wednesday on timing of the required second dose of the two currently used vaccines, saying the second dose can be given as late as six weeks after the first dose "if it is not feasible to adhere to the recommended interval."
The second dose of the Pfizer/BioNTech vaccine is typically given 21 days after the first, and for the Moderna vaccine, it is 28 days.
"This guidance is meant to provide some protocols that health departments can use so that they can address missed appointments," said Lori Tremmel Freeman, CEO of the National Association of County and City Health Officials.
Walmart among stores that will offer vaccine
Several thousand retail pharmacies will also begin administering vaccines as part of a federal program, with Walmart, CVS and Walgreens saying vaccinations will kick off Friday in participating stores.
More than 1,000 Walmart and Sam's Club pharmacies in 22 states will begin administering the vaccine as part of the Federal Retail Pharmacy Program, according to Walmart. It's unclear how many doses will be available.
The company said Tuesday it had worked with the CDC to identify pharmacy locations according to factors such as population density and infection rates, and also looked at locations in medically underserved areas.
Walmart and Sam's Club pharmacies are already vaccinating in 11 states under state allocations, according to the company's news release.
The Biden administration announced last week that the federal government will begin direct shipments of coronavirus vaccines to retail pharmacies starting Thursday, with a total of 1 million doses going to about 6,500 stores before eventually expanding.
CVS and Walgreens have said they will get around 420,000 of the 1 million doses available.
82% of educators not vaccinated, survey finds
Amid nationwide conversations on the steps needed for safe school reopenings, the country's largest teachers' union released a survey showing about 82% of the educators it represents have not yet received a vaccine.
The survey, conducted by the National Education Association, found that "the number of educators back to work in physical buildings far outpaces the number of educators being vaccinated."
Teachers have protested and voiced concerns about returning to the classroom after losing colleagues to the virus. But, according to a CNN analysis, teachers are not currently being prioritized for vaccination in 24 states.
After polling more than 3,300 of its members, the association found about 70% said they would feel safer about returning to in-person learning if they were vaccinated. About 64% said they are currently working in school buildings all or part of the time.
Perception of Covid-19 risk is lowest in months
Wednesday's Gallup poll showed Republicans and Democrats are willing to be vaccinated -- 51% and 91%, respectively.
Of people who are unwilling, 25% said they were concerned the vaccines were rushed; 22% want to see whether they're safe for others; 16% don't trust vaccines in general; and 9% want to see how effective they are. The poll also found that two-thirds of Americans were not satisfied with how the vaccination effort is going.
According to Johns Hopkins University on Wednesday, the US has recorded more than 27.2 million cases, far more than any other country, and more than 469,000 deaths.
Variants are complicating the outlook and concerning experts.
CDC data updated Tuesday shows more than 940 cases of Covid-19 variants first spotted in the UK, South Africa and Brazil have been reported in the US -- most being the highly contagious variant known as B.1.1.7, originally detected in the UK.
That number is concerning enough. But the CDC says it likely does not represent the total number of the variant cases, just those found by analyzing Covid-19 positive samples.
Americans' perception of risk is the lowest it's been in months, according to a new Axios-Ipsos poll. About 66% of people surveyed reported they thought there was a moderate or large risk in returning to pre-pandemic life. The last time that number was so low was in October.
Wednesday, the CDC said double masking can significantly improve protection. Researchers found that layering a cloth mask over a medical procedural mask, such as a disposable blue surgical mask, can block 92.5% of potentially infectious particles from escaping by creating a tighter fit and eliminating leakage.
