President Biden on Tuesday said every American who wants a Covid-19 vaccine should be able to access them by the end of July, and he expressed optimism that, "by next Christmas," the United States will "be in a very different circumstance … than we are today" in regard to the country's coronavirus epidemic.

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There are certain caveats to those predictions, however, including potential delays in vaccine rollouts across America and the threat of new, more contagious variants of the novel coronavirus, experts warn.

Biden's predictions for vaccine rollout, epidemic's future

During a town hall meeting hosted by CNN on Tuesday, Biden said he believes every American who wants to get vaccinated against Covid-19 will be able to do so "[b]y the end of July this year."

However, Biden later clarified that the United States should have enough doses "available" for every American who wants to get vaccinated by the end of July. Despite the clarification, Biden said he does not believe there will be significant delays in getting those doses administered to Americans.

Biden also expressed optimism that the country could see significant progress in combating its coronavirus epidemic by fall of this year. Although Biden said he did not want to "overpromise" on that progress, he said he believes that America will be "significantly better off than we are today" by September. In addition, Biden said he thinks that "by next Christmas [America will] be in a very different circumstance, God willing, than we are today" when it comes to the epidemic, and "[a] year from now," he thinks "that there'll be significantly fewer people having to be socially distanced, have to wear masks, etc."

However, Biden noted that those predictions aren't set in stone. Ultimately, he said, "we don't know. So I don't want to overpromise anything here. I told you when I ran and when I got elected, I will always level with you."

Biden admin will send more vaccine doses to states, opens federally backed vaccination clinics

Biden's comments came as his administration announced new moves intended to further accelerate the country's Covid-19 vaccine rollout.

For example, White House press secretary Jen Psaki on Tuesday announced that the federal government will increase the number of vaccine doses it is sending to states each week from 11 million to 13.5 million. The federal government also will begin sending two million doses per week directly to pharmacies, up from the current allotment of one million doses per week.

Further, the Federal Emergency Management Agency (FEMA) this week opened new, federally backed Covid-19 vaccination sites in California, with plans to open 100 such sites across the country in the coming weeks. On Friday, Department of Defense spokesperson John Kirby said the department had authorized an additional 20 teams, consisting of 4,700 servicemembers, to help staff the sites—on top of the five teams of 1,100 servicemembers the department authorized last week.

Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases and chief medical adviser to the White House's Covid-19 response, on Tuesday said he believes the United States likely will see "a sharp escalation in the number of people that get vaccinated and very little wait for people to get vaccinated" starting this spring, and Americans will see a substantial increase in Covid-19 vaccine availability in "late May and early June" of this year.

Experts caution that several factors could inhibit vaccine rollout, progress on epidemic

While public health experts and stakeholders have largely praised the Biden administration's recent moves to accelerate America's Covid-19 vaccine rollout, many have also cautioned that several factors could limit the rollout—as well as America's recent improvement in the country's coronavirus epidemic.

For instance, severe winter storms throughout the county this week caused hundreds of vaccination sites to shut down and "widespread delays" in vaccine shipments, CDC said Tuesday. The Washington Post reports that CDC spokesperson Kristen Nordlund in an email wrote, "Due to the severe winter weather currently impacting a large swath of the country, the U.S. government is projecting widespread delays in Covid-19 vaccine shipments and deliveries over the next few days."

According to the Post, Nordlund did not note which states or how many vaccine doses were affected by the delays. However, many states and localities have reported delays, and some organizations canceled vaccination events that had been scheduled in Alabama, Florida, Georgia, Illinois, Indiana, Missouri, New Hampshire, Pennsylvania, South Carolina, Tennessee, Texas, and more.

According to Politico, a CDC spokesperson said the agency "and federal partners are working closely with [affected] jurisdictions, as well as manufacturing and shipping partners, to assess weather conditions and help mitigate potential delivery delays and cancellation."

CDC data shows that, as of Tuesday morning, the federal government had distributed about 71.7 million doses of the country's two authorized Covid-19 vaccines, which each require patients to receive two doses of the inoculations a few weeks apart. Of those, about 55.2 million doses had been administered in the United States. That total includes about 39.7 million people who have received "one or more doses" of a vaccine and about 15 million who've received two doses, the data shows.

Separately, experts have also warned that emerging new variants of the novel coronavirus could threaten America's recent progress when it comes to the epidemic.

According to CDC data, the United States as of Tuesday reported 1,299 total cases of novel coronavirus variants across 42 U.S. states. That total includes:

• 1,277 cases of the B.1.1.7 variant first identified in the United Kingdom, which research suggests is more transmissible and deadly, and possibly less susceptible to Covid-19 vaccines, than earlier variants of the virus;
• 19 cases of the B.1.351 variant first identified in South Africa, which research suggests is more transmissible and less susceptible to Covid-19 vaccines than earlier variants of the virus; and
• Three cases of the P.1 variant first identified in Brazil, which research suggests is more transmissible and less susceptible to vaccines than earlier variants of the virus.

During an interview with "Axios on HBO" that aired Sunday, Fauci said the newly emerging variants could create a "stumbling block" in America's recent progress in containing the country's coronavirus epidemic, despite the effectiveness of Covid-19 vaccines.

While "things are going in the right direction ... we're also going to be challenged by the appearance of variants or mutants that have appeared, some of which have a functional influence on how we're gonna respond to them," Fauci said. However, he added that, "[f]ortunately," Covid-19 vaccines may help to protect Americans against some of the new variants, at least to some degree.

Where America's coronavirus epidemic stands

Despite the new variants' increasing spread in the United States, recent data indicates America's coronavirus epidemic has improved since last month's peak in reported cases, hospitalizations, and deaths—though the reported rates of each of those metrics remain high.

According to data compiled by the New York Times, U.S. officials on Tuesday reported about 64,376 new coronavirus cases, though that total may be skewed because of a reporting lag over the President's Day holiday. As of Wednesday morning, officials had reported a total of about 27.8 million cases of the novel coronavirus since the United States' epidemic began.

According to the Times, the United States' average daily number of newly reported coronavirus cases over the past week was 81,200—down by 43% when compared with the average from two weeks ago, when the United States was in the midst of its worst peak in newly reported cases.

As of Wednesday morning, data from the Times showed that the rates of newly reported coronavirus cases were "staying high" in Alaska, South Dakota, and Vermont, which have each reported a daily average of at least 15 newly reported cases per 100,000 people over the past week. In contrast, rates of newly reported coronavirus cases were "staying low" as of Wednesday morning in Guam, Puerto Rico, the U.S. Virgin Islands, and 10 states. Those states are Hawaii, Idaho, Maine, Michigan, Minnesota, Missouri, North Dakota, Oregon, Washington, and Wyoming.

All other states and Washington, D.C., had been seeing comparatively higher rates of coronavirus transmission, but the daily average of newly reported coronavirus cases over the past seven days in those areas was "going down" as of Wednesday morning, according to the Times' data.

U.S. hospitalizations for Covid-19, the disease caused by the novel coronavirus, remained high as of Tuesday, but still were down significantly from record highs reported last month. According to data from The Atlantic's COVID Tracking Project, there were 64,533 Americans with Covid-19 hospitalized for treatment on Tuesday, including 13,616 who were receiving care in an ICU and 4,406 who were on a ventilator. Tuesday marked the twelfth consecutive day that fewer than 90,000 Americans with Covid-19 were hospitalized for treatment.

Similarly, the United States' rate of newly reported deaths linked to the novel coronavirus has declined over the past two weeks, though it also remains high. According to data from the Times, U.S. officials reported about 1,707 new deaths linked to the virus on Tuesday, though that total also may be skewed because of a reporting lag over the President's Day holiday. As of Wednesday morning, officials had reported a total of about 487,855 U.S. deaths linked to the virus since the country's epidemic began.

(Stolberg, New York Times, 2/17; Samuels, The Hill, 2/16; Garcia/Noveck, Associated Press, 2/16; Money, Los Angeles Times, 2/16; Schemm et al., Washington Post, 2/16; Nirappil et al., Washington Post, 2/16; Ehley, Politico, 2/16; Mitchell, The Hill, 2/12; CDC vaccine data, updated 2/16; CDC variants data, updated 2/16;  New York Times, 2/17; "COVID Tracking Project," The Atlantic, accessed 2/17; Talev, Axios, 2/15).