(CNN)If states are able to "diligently vaccinate" people against the coronavirus next year, the US could return to normal life by early fall, Dr. Anthony Fauci said Wednesday in an Facebook interview with California Gov. Gavin Newsom.
Although the Covid-19 vaccine rollout is off to a much slower start than expected, if the US is able to catch up, widespread vaccination could be possible beginning in April, said Fauci, the longtime director of the National Institute of Allergy and Infectious Diseases.
Government officials had initially promised at least 20 million vaccine doses would be administered by the end of December, but just days away from the end of the year, Centers for Disease Control and Prevention data shows about 12.4 million doses have been distributed and nearly 2.8 million have been administered.
"Let's say in April, it will be what I call open season, namely, anybody who wants to get vaccinated can get vaccinated," Fauci said in the Facebook interview. "If we then diligently vaccinate people in April, May, June, July, then we will gradually and noticeably get a degree of protection approaching herd immunity."
Fauci has estimated that herd immunity -- where enough people have antibodies to diminish the spread of the virus -- could likely be achieved if about 70% to 85% of the population gets vaccinated.
"By the time we get to the early fall, we will have enough good herd immunity to be able to really get back to some strong semblance of normality -- schools, theaters, sports events, restaurants," he said. "I believe if we do it correctly, we will be there by the early fall."
Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine, said vaccinations will have to increase to more than 1 million per day.
It's doable, he said, but, "Do we have the health system to do that? I'm not certain."
He said the federal government needs to step up and states need to get funding for the administering of the vaccines.
Trump administration officials told CNN that vaccine distribution is on track and blamed the gap on a lag in reporting data.
Assistant Secretary for Health Admiral Brett Giroir said he expects distribution to ramp up soon and that the US is on track to distribute 20 million vaccine doses by the first week of January.
"Of course, we need to be doing a better job, but all vaccine programs start somewhat slow," Giroir told CNN's Jake Tapper. He expects 30 million more doses to be distributed in January and potentially up to 50 million more in February. Both of the vaccines require two doses to be fully effective.
2 vaccines might win authorization early next year
Two new vaccines for Covid-19 may be authorized for use in the US in the coming months.
The Oxford-AstraZeneca Covid-19 vaccine that the United Kingdom approved for use on Wednesday may be authorized for emergency use in the US in April, according to Moncef Slaoui, chief scientific adviser for Operation Warp Speed.
That vaccine is in Phase 3 trials in the US, Slaoui said, and the vaccine is being manufactured ahead of the potential authorization.
"If everything goes well, that read-out and emergency use authorization may be granted somewhere early in April," he added. "By that time, several tens of millions of doses of this vaccine will have been manufactured."
In addition, Johnson & Johnson's single-dose vaccine may be authorized for emergency use in February and could be a "game changer" for the US, Slaoui said. Phase 3 trial recruitment for this vaccine has been completed.
"We feel more and more confident that readout of efficacy will take place during the month of January, and very likely an EUA submission will take place during the month of January," said Slaoui, referring to emergency use authorization.
The US has already authorized the use of two vaccines -- one from Pfizer/BioNTech and one from Moderna.
The vaccinations, and the reinforcements potentially on the way, come at a critical time. The US set two more devastating Covid-19 records as it counted down the hours to the end of what has been a calamitous year.
On Tuesday, the US recorded more than 3,700 deaths linked to the virus, a chilling new high. There were almost 3,700 additional deaths reported by Wednesday evening, according to Johns Hopkins University.
The US on Wednesday also reported the most Covid-19 hospitalizations, with 125,220 patients nationwide, according to the Covid Tracking Project.
Surge of hospitalizations across country
On a state level, Texas officials reported record-high hospitalizations Wednesday, with 11,992 Covid-19 patients across the state, while Georgia Gov. Brian Kemp said Tuesday a temporary hospital with an additional 60 beds could open within the next few days.
In Los Angeles County, hospitalizations are at an all-time high of 7,415, an increase of more than 500 in two days. With the surge in patients, some hospitals are running out of oxygen tanks.
"I actually think we're now beyond waves or surges and this is a viral tsunami that we are now experiencing," epidemiologist Dr. Robert Kim-Farley said.
Ambulances are sometimes waiting with patients -- with Covid-19 or other problems -- outside hospitals, the county's department of health services said.
"The demand is leading to lines of ambulances waiting to offload patients and hospitals having to open up new areas to treat patients," an emailed statement said. "We expect the ambulance diversion to continue as numbers of COVID-19 cases -- and the numbers of people needing hospital care -- continue to rise."
And experts have warned the US likely will see even worse Covid-19 numbers in January fueled by this month's holiday gatherings and travel.
And while the ongoing vaccinations continue to offer hope, it likely be months before the country will begin to see a meaningful impact, experts said.
One state did report good news with hospitalizations. Indiana Gov. Eric Holcomb told reporters he is lifting the statewide pause on elective surgeries because recent data show the hospital census is becoming more manageable.
UK variant discovered in Colorado and California
Health officials in a Colorado county believe they've found a second case of a coronavirus variant from the United Kingdom -- one that experts have said may be especially contagious.
The news came a day after the first known case of the variant in the US was announced in Elbert County. Both the confirmed case and the suspected instance involve men who work at the Good Samaritan Society assisted living facility in Simla, about 45 miles northeast of Colorado Springs, county health director Dwayne Smith told CNN.
"There is a lot we don't know about this new Covid-19 variant, but scientists in the United Kingdom are warning the world that it is significantly more contagious," Gov. Jared Polis said in a statement.
And the variant is "almost certainly" in multiple states, according to one expert.
"I think we will be seeing evidence of that in the days to come," said Dr. Atul Gawande, a member of the Biden-Harris transition Covid-19 advisory board.
"Exactly how prevalent it is, is the real question," he added. "If it's been spreading, how, how dominant is it?"
"We know it is a more contagious variant and that's a serious concern if it is only just now beginning to spread, given that our hospitals and ICUs, in particular, are already being filled."
In California, San Diego Supervisor Nathan Fletcher said a 30-year-old man with no travel history has the UK variant of the virus. Another person in the house has Covid-19 symptoms, officials said.
At least 27 countries have so far reported cases of the variant, per CNN reporting.
