The recent winter weather slamming the U.S. has delayed COVID-19 vaccine deliveries and forced vaccination sites to close.
The unforeseen setbacks have impacted all 50 states and left a backlog of about 6 million doses of vaccine and 2,000 vaccination sites left without power, according to White House senior adviser Andy Slavitt.
"We anticipate that all the backlog doses will be delivered within the next week, with most being delivered within the next several days," Slavitt said during a press briefing on Friday.
The chances of President Joe Biden's promise of over 600 million doses of vaccine delivered by the end of July could be in jeopardy, but Biden said Friday that he believes normalcy will return by the end of the year.
"God willing, this Christmas will be different than last, but I can't make that commitment to you," said Biden.
On Friday, Biden visited Pfizer's assembly line in Kalamazoo, Michigan, to get a first-hand look at production.
"Getting the vaccine and having it available is not the same as putting it in somebody's arm," he said. "This is going to be a continuous rolling effort."
MORE: Biden says he can't give a date when COVID-19 crisis will endPfizer announced Friday they're taking steps to simplify the distribution process. They've put in a request to the Food and Drug Administration to allow its vaccine, which usually requires ultra-cold storage, to be stored in regular freezers for up to two weeks after delivery, allowing vaccines to be more widely available.
"If there's one message to cut through to everyone in the country, it's this: The vaccines are safe. Take the vaccine when it's your turn and available. That's how to beat this pandemic," said Biden.
Los Angeles, facing vaccine shortages due to shipping problems exacerbated by the winter storms, opened the first COVID-19 mass vaccination sites run by the Federal Emergency Management Agency on Tuesday. Mayor Eric Garcetti said the slow down in distribution is detrimental to the hard-hit city.
"We are in a race against time, a race between infections and injections, and anything that slows down our progress is unacceptable," said Garcetti.
MORE: Serious COVID-19 vaccine reactions are rare, says new CDC reportIn North Carolina, 91-year-old Lilly Pena said she couldn't get a second dose despite waiting in line twice.
"I'm very frustrated," she said. "Even I'm angry."