Dr. Fauci: US could see 'further suffering and further death'

In some places, the efforts seem to be working. In states including Arizona, Texas and Florida, which reopened without effective safety protocols and saw rapid case spread since June, new cases have flattened or slightly decreased recently. But that doesn't mean the states are out of the woods just yet, and it's still too early to tell how long the trend will last.

States crack down on social gatherings

Birx said that among the states officials are tracking, there seems to be a "household" pattern of infections that starts with young people, usually less than 30 years old. Those residents, who are usually asymptomatic, then transmit the virus to their parents who then transmit it to other, older residents, she said.

In Mississippi, about 80% of surveyed coronavirus patients said they had attended a social gathering, including funerals and birthday parties, where people weren't adhering to social distancing. And in New Jersey, health officials said they have seen multiple outbreaks arising from gatherings of young people.

To stop those infections, states have cracked down on congregate settings -- like bars --- and pleaded with younger groups to heed guidelines including wearing masks and social distancing.

In Columbus, Ohio, the city council approved legislation that would require bars and restaurants to close at 10 p.m. each night starting Tuesday.

"Our city like many others across the country are seeing an increase in COVID-19 cases, and there is clear evidence of community spread -- especially indoors in places where groups are gathering," Mayor Andrew Ginther said in a statement. "We're also seeing a clear increase among younger people, and we know that bars and nightclubs have been the source of outbreaks locally."

In Kentucky, the governor also imposed new restrictions on restaurants, shut bars down for the next two weeks and recommended schools postpone in-person instruction until late August.

"It's time to do the things that we got to do, given the stage that we're in, to control this virus," the governor said. "And I know there ended up being questions out there about 'why didn't you take this step four weeks ago, or six weeks ago?' Listen, this virus doesn't care about our schedules."

New York and Miami issuing hundreds of coronavirus-related citations

Despite new restrictions, some local leaders have voiced their opposition to the mandates and others -- like sheriffs -- have said they won't be enforcing the rules.

But in Miami and New York, officials have doubled down on enforcement.

New York Gov. Andrew Cuomo said Monday the state had issued at least 132 violations over the weekend to bars and restaurants for not following coronavirus-related regulations. Most of them were in New York City, Cuomo said.

Since the state began reopening, at least 40 establishments have had their liquor licenses suspended as a result of violations and 10 of those suspensions occurred since Friday, the governor said. The lack of compliance with social distancing policies in bars and restaurants among young people is a concern for his administration, Cuomo said.

Meanwhile, in Miami-Dade County -- which has reported more cases than all but 12 states -- police issued more than 300 citations in 10 days to individuals and businesses who weren't abiding by the local mask order.

"The growth rate (of cases) has shown flattening since we implemented the masks in public rule and we're following the advice of our health care professionals and our hospital administrators who are telling us that what we have to do now is focus on enforcement," Miami Mayor Francis Suarez told CNN Sunday. "We created a special task force just for that and we've been issuing hundreds of tickets over the course of the week."

Phase 3 of vaccine trial in US underway

Officials are now using precautions like face masks and social distancing to curb the spread of the virus, but soon the country may have even more help.

Vaccine maker Moderna started its final trial of a coronavirus vaccine in the US Monday, and volunteers from dozens of sites across the country will participate in the study, Fauci said Monday.

"There are 89 sites distributed throughout the country," Fauci said. "They are widely distributed as a matter of fact in areas where there is clearly as of right now active infection going on."

There are expected to be 30,000 adult volunteers in the Phase 3 trial. The first patient was dosed at a site in Savannah, Georgia, on Monday.

"I think we are going to get a good sampling of the activity of virus transmission that's currently going on in the country."

Fauci said that a vaccine likely won't be widely available to people in the US until "several months" into 2021.

And this part of the US trial can't be sped up, a vaccine expert told CNN Monday.

"Typically vaccine development programs take 15 years on average. This vaccine development program is probably going to take a year and a half," said Dr. Paul Offit, the director of the Vaccine Education Center and professor of pediatrics at the Division of Infectious Diseases at Children's Hospital of Philadelphia.

"The one thing you can't truncate or coalesce or overlap is the Phase 3 trial," Offit said. "The proof is in the pudding. The Phase 3 trial's the pudding and now you're going to test hopefully 10, 15, 20,000 people that will get this vaccine, 15,000 people that will get placebo and you'll see to what extent this is really safe and you'll see to what extent it's effective."