The White House vaccine chief has revealed that the first Americans could be vaccinated in just a few weeks - as early as December 11, 2020.
Now, the government has noted that the United States is expecting to start COVID-19 vaccinations by December 11, 2020.
According to Slaoui, 20 million people across the U.S. could be vaccinated in December and around 30 million people would be vacinated per month after that.
Meanwhile, the final results of the vaccine trials are still being computed.
Slaoui said that with the level of efficacy shown by both Pfizer and Moderna vaccines, "70% or so of the population being immunized would allow for true herd immunity to take place, that is likely to happen somewhere in the month of May, or something like that based on our plans".
"I'm very, very concerned about the hesitancy as it exists", Slaoui told ABC earlier on Sunday.
"The roll-out for people between 18 and 50 years old could start late January, after older people and front line workers are vaccinated, according to the Telegraph".
A Gallup poll from Tuesday showed that 58 percent of Americans said they would get a coronavirus vaccine and 42 percent said they wouldn't.
If the committee issues an emergency use authorization for Pfizer's Covid-19 vaccine, it could be rolled out as soon as the next day.
"When the American public hears that, you should be assured that that is the case and if you get an overwhelming majority of the people vaccinated with a highly efficacious vaccine, we can reasonably quickly get into herd immunity that would be a blanket of protection for the country", Dr Fauci said.
Slaoui said that while the trials had ensured only short-term safety, decades of experience showed that almost all adverse effects of vaccines occurred within 40 days of being administered, while the current trials protectively covered 60 days.
"Most people need to be immunised before we can go back to a normal life", he said.
In the North State there are five new cases reported Sunday in Modoc County.
Fauci cautioned that vaccines have to come, they have to be deployed and fundamental public health measures can't be abandoned.
Experts have said that initially there won't be enough vaccine for everyone.
In the United States, the first people to receive the Pfizer vaccine would likely include doctors, nurses and front-line emergency medical personnel, as well as those at the highest risk of severe illness and death from the virus, Slaoui said.
It is learnt that an FDA vaccine advisory committee will meet on December 10 to take a decision in this regard.
There are new efforts on the race for a vaccine for Covid-19.
Experts have said that the availability of Pfizer vaccine in India may be hard as it requires extremely cold temperatures of minus 70 degrees celsius for storage.