Senator Lamar Alexander of Tennessee, chairman of the committee, opened the hearing with comments on wearing masks, saying the issue shouldn't be as politicized as it's become and that he's asked President Donald Trump to wear a mask to set an example. For now, the committee's leading Republican stressed wearing a mask - and said Trump, who notoriously shuns them, needs to start because politics is getting in the way of protecting the American people.
"The president has plenty of admirers, they would follow his lead", he added. "You made an estimate back in March between 100,000 and 200,000, but we have a lot more information now and we are already at 126,000 deaths".
Also during the hearing, Fauci said he's "concerned" about how some states have gone about reopening their economies and said he's observed some states "skipping steps" on federal government guidelines.
Countries including the USA are scrambling to develop a vaccine, and Fauci has said one could be available by the end of 2020 or early 2021.
The urgent message came during a hearing on the latest efforts by the USA government to contain the pandemic, as several states struggle to contain the virus amid rising cases and state reopenings.
Fauci said it's unlikely any vaccine will be 100% protective against the coronavirus, and he noted the best vaccine available, which protects against measles, is 97% effective with two doses.
FDA Commissioner Stephen Hahn said vaccine makers also must test their shots in diverse populations, including minorities, the elderly, pregnant women and those with chronic health problems.
'This is particularly as important as we know that some people are skeptical of vaccine development efforts, ' he continued, adding that 'public confidence in vaccines is so important'.
'I can tell you that when they announced that the other day, obviously there was substantial disappointment with American Airlines, ' Redfield said. If we don't fully implement the widespread testing, contact tracing programs, and social distancing practices that everyone seems to agree that we need, can we expect these spikes in infection to keep happening in different places around the country?
"I think there was a lot of wishful thinking around the country that, "hey it's summer".
He said this was due to the combination of a vaccine that is potentially only partially effective, and the large number of Americans who might refuse to get it.
"We saw visually in clips and in photographs of individuals in the community doing an all or none phenomenon, which is unsafe", he said.
Based on most estimates, at least 70 percent of Americans need to be immune to the SARS-Cov-2 virus to achieve herd immunity that halts the COVID-19 epidemic.