KEY POINTS
  • Covid-19 cases were growing by 5% or more, based on a weekly average to smooth out daily reporting, in 11 states as of Sunday, according to a CNBC analysis of data collected by Johns Hopkins University, an increase from eight states on Friday.
  • The states were Alaska, Arkansas, Connecticut, Delaware, Maine, Nebraska, New Hampshire, New Jersey, Rhode Island, Wisconsin and Wyoming.
  • Wisconsin hit a record high in its average of daily new cases, reporting 1,353 new infections, a roughly 32% increase from a week ago.

Coronavirus cases continued to grow over the weekend in nearly a dozen U.S. states as Dr. Anthony Fauci, the nation's leading infectious disease expert, warns about the nation's worrying level of new infections.

Covid-19 cases were growing by 5% or more, based on a weekly average to smooth out daily reporting, in 11 states as of Sunday, according to a CNBC analysis of data collected by Johns Hopkins University, an increase from eight states on Friday.

The states were Alaska, Arkansas, Connecticut, Delaware, Maine, Nebraska, New Hampshire, New Jersey, Rhode Island, Wisconsin and Wyoming. Wisconsin hit a record high in its average of daily new cases, reporting 1,353 new infections, a roughly 32% increase from a week ago, the Hopkins data shows. Kansas and Montana both hit record highs for new deaths.

The new data comes two days after Fauci, director of the National Institute of Allergy and Infectious Diseases, said current data on the U.S. Covid-19 outbreak is "disturbing," disagreeing with President Donald Trump, who said the U.S. outbreak was "rounding the corner."

A bicycle rider in Liberty State Park wears a mask during the fourth phase of reopening on August 30, 2020 in Jersey City, New Jersey.

While cases are growing in 11 states, the overall daily average of new cases in the U.S. is declining. Over the past seven days, the country has reported an average of about 34,300 new cases per day, down more than 15% compared with a week ago, according to a CNBC analysis of Hopkins data. That's far lower than the roughly 70,000 new cases a day the U.S. was reporting weeks ago. 

Still, the 34,300 new cases a day is alarmingly high, infectious disease experts say, and U.S. health officials fear the outbreak could get worse as the nation enters the fall and winter seasons. Health officials have repeatedly warned that they are preparing to battle two bad viruses circulating later this year as the coronavirus outbreak runs into flu season. Earlier this month, Fauci said daily new cases were "unacceptably high" this close to fall. 

Health officials say the U.S. is unlikely to return to "normal" until there is a safe and effective vaccine. There are currently no U.S.-approved drugs or vaccines for the virus, though U.S. regulators have authorized some treatments for emergency use for hospitalized patients. 

Earlier in the day, the CEO of Pfizer, one of the frontrunners in the race for a Covid-19 vaccine, said its vaccine could be distributed to Americans before the end of the year if found to be safe and effective.

The company is currently in late-stage testing and hopes to enroll up to 44,000 participants.

Albert Bourla told CBS' "Face the Nation" that the drugmaker should have key data from its late-stage trial for the Food and Drug Administration by the end of October. If the FDA approves the vaccine, the company is prepared to distribute "hundreds of thousands of doses," he said. 

Even if a vaccine is approved to be distributed before the end of the year, it will likely be in short supply. The vaccine will likely require two doses at varying intervals, and states still face logistical challenges such as setting up distribution sites and acquiring enough needles, syringes and bottles needed for immunizations.

For now, leaders can stop new outbreaks by practicing the "basics" of public health and disease control, medical experts and officials say.

The World Health Organization recommends that people wear masks as a way to slow the spread of the virus. Scientists say Covid-19 can spread through respiratory droplets that pass when an infected person coughs or sneezes. Studies suggest the masks may serve as a helpful barrier to spreading infection.

The agency also recommends people wash their hands regularly, maintain their distance from others and avoid going to crowded places. If you have a fever, cough and difficulty breathing, seek medical attention, but call by telephone in advance if possible and follow the directions of your local health authority, the WHO said.