(CNN) — Despite challenges with distributing and administering Covid-19 vaccines, the US “can and should” vaccinate 70-85% of adults by the end of summer, infectious disease expert Dr. Anthony Fauci says.

That could bring a semblance of normalcy by the fall, the director of the National Institute of Allergy and Infectious Diseases said.

“When you put …. the pedal to the floor, you can get it done,” Fauci told CNN’s Chris Cuomo on Thursday night.

If the US were to administer 1 million shots per day — the pace required to meet President Joe Biden’s goal of giving 100 million shots in his first 100 days in office — it would take until the end of 2021 to fully vaccinate 75% of US adults, assuming every recipient needs two shots, according to a CNN analysis.

But that time frame would shrink if some people received one-dose vaccines. Johnson & Johnson produced one such candidate and is expected to report on Phase 3 clinical trials by the end of the month.

And Fauci said Friday he believes the US can go faster than 100 million shots in 100 days.

“I’d like it to be a lot more,” Fauci told CNN’s John Berman. “The goal was set, but you don’t want to get fixated on, ‘Was that an undershoot or an overshoot?’

“If we can do better than that, which I personally think we likely will, then great.”

The US recently recorded 1 million new shots in a 24-hour period, according to changes in US Centers for Disease Control and Prevention data from Wednesday morning to Thursday morning. That’s only the second time a one-day increase rose above 1 million.

Fauci’s assessment offers a glimmer of hope as forecasts predict the death toll from the virus will likely top 500,000 within the next month.

“The only way to solve a problem is to own it,” he said Thursday. “Everybody wear a mask. Everybody adhere to the public health measures. Get the vaccine out as expeditiously as possible. Do everything we can to get the doses available and to get them into people’s arms.”

Seniors spend hours waiting in LA.

More than 15 million people in the US have received at least one shot of a Covid-19 vaccine. Almost 2.4 million of them received a second dose, according to CDC data last updated Thursday morning.

Some state and local officials say they aren’t getting the vaccines fast enough to meet demand.

In Georgia, officials are seeing high numbers of cases, hospitalizations and deaths, and the 120,000 doses allotted per week to the state is not enough to vaccinate seniors and other high-risk residents, Gov. Brian Kemp said.

“We will still have far more demand than we have supply,” Kemp said.

Constraints on supply in New York City means there are not enough doses to vaccinate members of the city’s police and fire departments, the agencies told CNN on Thursday. There are still enough for those who already have appointments made and those who had already received their first dose, the fire department said.

Lines at Los Angeles’ Dodger Stadium on Thursday were filled largely with people over 65 years old, with some waiting for five hours for the vaccine, Mayor Eric Garcetti said.

“There may be a wait… so use the restroom beforehand, bring water and snacks, and make sure your gas tank is filled up or your car is charged,” he said.

Biden’s pick for Surgeon General, Dr. Vivek Murthy, said the US needs to do more to speed up the vaccinations.

“We cannot take a year in order to get to the critical levels of vaccination that we need in this country,” Murthy told CNN’s Wolf Blitzer on Thursday. “We’ve got to get there sooner.”

Even with reports of many people waiting in line, about six in 10 Americans don’t know when or where to get a coronavirus vaccine, according to a new report from the Kaiser Family Foundation.

Most Americans don’t know when or where they can get a vaccine, including older Americans, who are already eligible to get a vaccine in a growing number of states,” KFF President and CEO Drew Altman said in a news release Friday. “Understandably large numbers of people are frustrated, angry and confused.”

New vaccines could be on the way

Officials hope new coronavirus vaccines will be approved and help speed up the administration.

Currently, the US has approved vaccines by Pfizer and Moderna.

However, Johnson & Johnson, assuming it receives FDA approval, plans to have “enough vaccines for 100 million Americans by spring,” board member Dr. Mark McClellan told CNBC on Thursday.

Fauci said the company’s vaccine is “right around the corner” from seeking emergency use authorization from the FDA.

“They’re probably a couple of weeks away from getting the data looked at, to have the FDA evaluate whether or not we’re in a situation where we could move ahead and start thinking about getting it out into the public,” he said Thursday.

That candidate would come with advantages, he said. It will come in a single shot and it won’t need to stay in the cold climate that has made storing and transporting existing vaccines so difficult, Fauci said.

As for another candidate in Phase 3 trials, from AstraZeneca, that is “a bit behind, but not too far behind,” Fauci said.

Last week, the federal government’s Operation Warp Speed program’s chief adviser said he hoped the AstraZeneca candidate, if data shows it to be effective, could receive US authorization by the end of March.

“Hopefully the vaccine again is efficacious, as has been shown in the trials conducted in Brazil and in the UK,” Operation Warp Speed chief adviser Moncef Slaoui said. “So maybe an approval somewhere towards the latter part of the month of March, and a significant number of doses available around that time.”

The-CNN-Wire

™ & © 2021 Cable News Network, Inc., a WarnerMedia Company. All rights reserved.