More Than 90 Percent of Americans Still Susceptible to Coronavirus, CDC Director Warns

The director of the U.S. Centers for Disease Control and Prevention revealed Wednesday that more than 90 percent of the American population remains susceptible to COVID-19, despite the fact that the U.S. has had the most reported cases of any country in the world.

Dr. Robert Redfield joined other top health officials in testifying in front of the Senate Committee on Health, Education, Labor and Pensions to discuss federal response to the coronavirus pandemic. The hearing took place Wednesday, just one day after the U.S. surpassed 200,000 virus-related fatalities, according to data published by Johns Hopkins University.

Committee chair Lamar Alexander, a Republican from Tennessee, questioned Redfield on how many Americans have been infected by COVID-19. Alexander said he spoke to the British ambassador to the U.S. Tuesday, who told him that government studies based on serology testing showed that between 5 and 25 percent of the United Kingdom's population had been exposed. "What about the American population?" Alexander asked Redfield.

The CDC is in the process of conducting a similar study across the entire U.S. measuring serology, which is the examination of blood serum, Redfield said.

"The preliminary results on the first round show that a majority of our nation, more than 90 percent of the population, remain susceptible," he testified, adding that it varied based on geographic location. States that have had higher rates of infection have higher numbers of people who've been exposed to the virus, Redfield explained.

The CDC hopes to have the numbers finalized and the study published within the next week or so, Redfield said, but it already suggests that "the majority of Americans are susceptible to this virus."

Alexander repeated the numbers to Redfield, confirming with him that, based on the preliminary indications from serological testing and studies, as many as 90 percent of Americans still have not had coronavirus.

The numbers are in line with data published by Johns Hopkins' COVID-19 tracker. The U.S. has reported 6,902,930 cases as of September 23. According to the U.S. Census, the country's current population is hovering around 330 million people. This means that slightly more than 2 percent of the total U.S. population has had a documented coronavirus case.

In response to Newsweek's request for comment, a spokesman for the CDC pointed to the organization's website breaking down its COVID-19 serology surveillance. Serology tests look for antibodies in blood. If they are found, it means the person has had a previous infection, as antibodies are the proteins which can fight off infections, the website states.

Reported coronavirus disease cases "likely represent only a fraction of all SARS-CoV-2, the virus that causes COVID-19 infections," according to the website. To better understand the number of Americans affected by the virus, the CDC is conducting large-scale geographic seroprevalence surveys, which involve performing serology testing on blood samples that were initially used for other purposes.

Robert Redfield
CDC Director, Dr. Robert Redfield, testifies during a US Senate Senate Health, Education, Labor, and Pensions Committee hearing to examine Covid-19, focusing on an update on the federal response in Washington, DC, on September 23, 2020. Alex Edelman / POOL / AFP/Getty

Dr. Anthony Fauci, the nation's leading infectious disease expert and member of the White House's coronavirus task force, also testified during the hearing. In his opening statement, Fauci said he believed Americans would know by November or December whether the vaccines currently being developed are effective.

"We feel strongly that if we have a combination of adherence to the public health measures together with a vaccine ... we may be able to turn around this terrible pandemic which we have been experiencing," Fauci said.

Each member of the panel, which also included Assistant Secretary for Health Dr. Brett Giroir and Dr. Stephen Hahn, director of the Food and Drug Administration, said they had confidence in the FDA's vaccine development process.

"If a vaccine is shown to be and proven to be and authorized by the FDA to be safe and effective, I certainly would take that vaccine. I would recommend to my family that they take that vaccine," Fauci said.

Fauci's comments come amid news that Johnson & Johnson has begun Phase 3 trials for its coronavirus vaccine, the final stage of clinical trials. It plans to enroll 60,000 participants and may require just one dose instead of two, unlike many of the vaccine competitors, the New York Times reported.

Update (09/23/20, 7:51 p.m.):This article has been updated to include more information from the CDC.

More Than 90 Percent of Americans Still Susceptible to Coronavirus, CDC Director Warns | News