(CNN) More than 200,000 Americans have lost their lives to Covid-19 since the start of the pandemic, and the country is now transitioning into a new season with worrisome trends.
The devastating death toll comes ahead of what experts caution could be a complicated flu season. In the next three months, another 150,000 people could lose their lives from Covid-19, according to a projection by the University of Washington's Institute for Health Metrics and Evaluation (IHME).
"We're entering into the fall and into the winter, and that means there's going to be more indoor things than outdoor things," Dr. Anthony Fauci said Tuesday during the Atlantic Festival. "Going into that situation, I would like to have seen the baseline of where we are -- the daily number of infections -- come way, way down and not be stuck at around 30- to 40,000 per day."
At least 22 states now report a rise in new cases, most of them in the country's heartland and Midwest. That number is a remarkable difference since last Monday, when only nine states reported an upward trend in cases. As of early Wednesday morning, seven states reported a decline of new cases, according to data from Johns Hopkins University.
Even after all those deaths and 6.9 million confirmed cases, more than 90% of Americans remain susceptible to the virus, said Dr. Robert Redfield, director of the Centers for Disease Control and Prevention.
"CDC is in the process of a very large, sequential study across the entire United States, measuring serology," Redfield told the Senate Health Committee on Wednesday. "The preliminary results on the first round show that a majority of our nation -- more than 90% of the population -- remains susceptible."
At the Senate hearing, Redfield also explained why a document posted to the CDC's website that explained how Covid-19 spreads was subsequently removed.
"There is going to be a technically reviewed document on this issue coming on the website," Redfield said. "But the one that was posted on Friday was not technically reviewed, and as a consequence the career scientists at CDC took it down, put up the technically reviewed document, until the new technology review document can be posted."
Two more vaccine makers will probably have their candidates in the final stage of trials, Phase 3, in the next few months, National Institutes of Health Director Dr. Francis Collins said Wednesday on CNN.
There are now four Phase 3 trials underway in the United States, with Johnson & Johnson beginning its final phase Wednesday.
That's thanks to the government's Operation Warp Speed, meant to speed up the development of a safe and effective way to immunize people from the virus.
"Let me just say Operation Warp Speed, which has been supporting all of this with taxpayers' money, is responsible for the fact that this trial started today in Phase 3," said Collins.
"Initially, we were just going to be at Phase 1 for Johnson & Johnson in September, and because of the support and all the logistics, and frankly the financial support for Warp Speed, they were able to speed that up very substantially, and that is impressive work."
Dr. Fauci, director of the National Institute of Allergy and Infectious Diseases, said at the hearing that a "large proportion" of the United States will not be vaccinated this year, even if one is approved by then, echoing what others, including Redfield, have said, and it may be spring 2021 before they are widely available.
The first doses available probably will go to health care providers and vulnerable people with underlying conditions, Fauci said.
Getting into January and February, we potentially could have "a total of about 700 million" doses, he said.
"We're not going to have all of the doses available, for example, by the end of December, they will be rolling in as the months go by," Fauci said. "By the time you get to maybe the third or fourth month of the 2021, then you'll have doses for everyone," he said.
Fauci told the committee that we "need to be careful" about what long-term effects Covid-19 might leave with people.
"I think we need to be careful and just watch what happens because one of the possibilities that could develop, is that a) it could clear up, and they have no problem for the rest of their lives," Fauci said.
"The other things is that they could wind up when you have inflammation, you could have scarring, that could lead to arrhythmias later on, or that could lead to cardiomyopathies," he explained.
The virus, still running unabated in many US communities, is raising new alarm in states such as Kentucky and Wisconsin, which has one of the highest Covid-19 positivity rates in the nation, higher than 16%.
Wisconsin's governor declared a new public health emergency this week following a surge of cases among young people and issued a new order for face coverings. The state is experiencing "unprecedented, near-exponential growth," of the pandemic, according to a statement from Gov. Tony Evers' office.
Kentucky reported a spike in its Covid-19 positivity rate after several counties saw a surge in cases.
"This virus is deadly, it's real and it is harming, killing us," Gov. Andy Beshear said Tuesday during a news conference. "And on a day where we've lost 200,000 ... it looks like cases are back on the rise."
Covid-19 is now the third-leading cause of death in the US, according to the most recent available data from the CDC.
Still likely months away from an available vaccine, experts and public health officials maintain the best way to hold the virus down is universal mask wearing and social distancing.
The rise in cases also comes after several colleges reported outbreaks on campus and many opted to move classes online. Across the US, more than 59,000 Covid-19 cases have been reported among college students and staff.
In North Carolina, university officials announced UNC Charlotte would resume in-person instruction on October 1 following consultation with local health officials.
The university says it has "de-densified" dorms and given every student an individual room, limited indoor gatherings to 10 people and taken several other steps to control infections.
In Vermont, Middlebury College announced 22 students were barred from the school's campus following "significant Covid-19 conduct violations" over the week.
The students' punishment includes having their on-campus housing privileges revoked, and they will not be allowed to study, take courses, or visit other students on-campus, Dean of Students Derek Doucet wrote in a statement.
In hopes of stemming further transmission of the virus by welcoming students back in person, many school districts across the country also began the new academic year with virtual instruction.
On Tuesday, the Miami-Dade County school board voted unanimously to reopen school buildings no earlier than October 14. A phased opening will begin that day for students in pre-K, kindergarten and first grades and students with special needs. The district's reopening will be completed by October 21, two weeks later than what was originally proposed by the superintendent.
Miami-Dade is the largest school district in the state and one of the largest in the country, with about 345,000 students and more than 40,000 employees.
The school board's decision comes after many Florida public schools already reopened their doors last month. Since then, the number of children under 18 who have contracted Covid-19 across Florida jumped 26% by mid-September, state data showed.
CORRECTION: This story has been updated to correct Covid-19's ranking among causes of death in the US, according to the latest available CDC data. It is currently third.