WASHINGTON, D.C. — Virus mutations that could accelerate the spread of COVID-19 and vaccine distribution challenges are two of the main issues facing the country as states work to get shots in arms, Biden administration health officials told reporters Wednesday.

If the country continues on its current trajectory, the United States will report between 479,000 and 514,000 total COVID-19 deaths by Feb. 20, Centers for Disease Control and Prevention Director Rochelle Walensky said.

Though the Biden administration promised Tuesday to increase states’ vaccine supply by 16% and said it would have 600 million doses available by the end of this summer, health officials warned that shots delivered does not necessarily correlate to shots in arms. Americans should be prepared to wait several months before getting inoculated, as distribution problems could slow the process, officials warned.

Meanwhile, the nation faces growing risks as the coronavirus’s new variants mutate rapidly.

The National Institutes of Health and the CDC are trying to stay ahead of the mutations by monitoring strains from the United Kingdom and South Africa, but Biden administration officials said the agencies need more support from Congress.

The two approved vaccines, one by Pfizer and BioNTech and another by Moderna, both have enough of a cushion to protect against these two strains of the virus, said Dr. Anthony Fauci, the nation's top infectious disease expert at the NIH. Still, scientists expect the coronavirus will continue to mutate.

The CDC and NIH are working with drug and vaccine makers to develop what they call boosts that would use the same platform as the vaccines and incorporate an immunogen that combats the new strain. To successfully do that, scientists need to stay a step or two ahead of the virus’ trajectory.

States are currently collecting virus strains, and scientists are conducting genomic surveillance of the virus’ impact on the antibodies produced by the approved vaccines and vaccines currently under review.

But congressional aid would provide more resources to detect new strains of the virus. The coronavirus relief package lawmakers are debating would include money to step up the sequencing effort and help scientists detect new strains when they first start to emerge, Walensky said.

Thus far, the U.K. variant has shown a very slight impact on vaccine-induced antibodies but nothing else, Fauci said, so that is not enough to diminish the vaccine’s effectiveness.

“Things may be a little more problematic” with the South African strain, Fauci said, because it weakens vaccine-induced antibodies in multiple ways. So far, this isn’t enough of an effect to minimize the Moderna and Pfizer vaccines’ efficacy. But the situation may soon change.

“We have to be concerned looking forward to what the further evolution of this might be,” Fauci said.

The quick-spreading strain from the U.K. has already been discovered in several states, but the potentially more dangerous South African strain is not known to be here yet.

Despite the concern about the mutations, Walensky cited “some hopeful signs” about the state of the pandemic, including that last week the seven-day average of new cases decreased by 21% and the rate of new hospital admissions due to COVID-19 decreased by 15%.

Still, the country faces a mounting death toll.

Another argument for Congress to approve Biden’s proposed package is an interest in providing more funding for manufacturing and distributing the vaccines, including setting up more vaccination sites and bringing on board more vaccinators. Jeff Zients, the White House coronavirus response coordinator, said that package would also help increase the nation’s testing capacity and shore up the supply of protective gear.

Zients also said that the Department of Health and Human Services will increase the number of people able to serve as vaccinators by allowing recently retired doctors and nurses to administer shots and allowing anyone who is licensed in a state to give shots across state lines.

Administration officials are still weighing how to use the Defense Production Act to speed the manufacturing of more vaccines. The Biden administration’s announcement Tuesday included the news it would purchase an additional 200 million vaccines that would be available this summer.

Andy Slavitt, a White House senior adviser for COVID-19 response, said officials are still exploring whether to direct other specific companies to manufacture vaccines by Pfizer or Moderna that were authorized by the Food and Drug Administration. Challenges to manufacturing vaccine in that way include the difficulty of retrofitting factories.

The administration wants to be clear that manufacturing vaccines will not automatically translate into vaccinations, Slavitt added. While additional vaccines are expected to be produced by this summer, it takes time to distribute them across the country and convince Americans of their safety and efficacy.

“I don’t want you to hear that just because they will be manufactured and produced by a certain date that that is the same thing as taking every step necessary to get them to the public,” he said.

___ (c)2021 CQ Roll Call Distributed by Tribune Content Agency, LLC