Trump, Pence try to manage coronavirus response amid new fears it could spread Vice President Mike Pence chaired an inter-agency meeting on the virus.

A day after President Donald Trump declared Vice President Mike Pence the point person on the U.S. government's response to the coronavirus, the administration on Thursday continued to try to stem confusion over its handling of the outbreak.

But the stock market, which Trump has indicated is key reason behind the new effort and "will recover," dropped for the fourth day in a row -- down almost 1200 points, the biggest point drop ever and its worst week since the 2008 financial crisis.

The administration has directed all coronavirus communications and statements must be first vetted by and coordinated through the Office of the Vice President, including those coming from the Health and Human Services Department and the Centers for Disease Control, senior level White House sources confirmed to ABC News. Thursday afternoon, Pence said the risk to Americans "remains low."

He made the comment, when as part of the effort to reassure the public, he headed to the Department of Health and Human Services to hold a photo op with HHS Secretary Alex Azar and the administration's expanded task force on the virus.

Until Trump's announcement, Azar had been leading the administration's effort, chairing a task force on the situation. There was an awkward moment when a reporter asked Pence, "Can you clarify who in charge of the task force? Is it you or is it Secretary Azar?" a reporter asked with Azar sitting next to Pence.

Pence said he was.

"The president has asked me to lead our administration's effort in response to the coronavirus. I'm leading the task force. We'll continue to rely on the secretary's role as chairman of the task force and the leader of Health and Human Services," Pence said. "But the president wanted to make clear that we're going to bring a whole government approach to this."

Earlier, Pence said Trump had asked him to "lead the effort at the White House of our administration's response to the coronavirus, so we'll be working closely with this task force."

"This is the time when the president's made clear we want all hands on deck," he added.

Azar said at a White House news conference Wednesday he would remain in the task force chairman's role, even though Trump said at that same press conference that he wanted Azar to "focus on" his regular duties.

The secretary did not learn of the decision to make Pence the lead until just before Trump announced it publicly, three sources told ABC News.

On Thursday morning, Azar said at a hearing on Capitol Hill that he had been consulted about Pence's role before it was announced, although he did not say when. When he heard about it, he testified, "I said, quote, 'That’s genius.'"

While it's not unprecedented for the White House to clamp down on messaging during major news events, President Barrack Obama's Ebola Response Coordinator, Ron Klain, has taken issue with the directive that all coronavirus communication must go through Pence, citing the potential that this White House might censor information.

The vice president said Wednesday that he would "continue to bring that team together, to bring to the president the best options for action" and would reach out to state and local officials.

House Speaker Nancy Pelosi said she spoke to Pence Thursday morning and "expressed to him the concern that I had of his being in this position."

As Indiana's governor in 2015, Pence was criticized for his response to the state's worst outbreak of HIV in its history and the nation's first HIV outbreak linked to the injection of oral painkillers. He took two months to declare a state of emergency and opposed a clean-needle exchange over the advocacy of health officials.

Studies in medical journals have said the epidemic could have been prevented if the state had acted faster.

"This is about resources; it's also about personnel," Pelosi said. "It's also about respect for science, for evidence-based decision making, and it's about having so much of that talent that we are so proud of in our public health sector be available in other countries so that we can get a true … and accurate assessment of what is happening in other countries.”

Overall, Pelosi said, “Up until now the Trump administration has mounted an opaque and chaotic response to this outbreak."

At the Wednesday press conference, Trump made a rare appearance in the White House briefing room, taking questions for the first time and trying to portray a sense of calm amid rising fears over the virus, called COVID-19.

But some of his comments did not clear up some of the public's confusion.

While health officials standing alongside him said cases would increase, Trump at times questioned whether that was true and downplayed the threat.

A day earlier, a Centers for Disease Control and Prevention official had warned Americans of "significant disruption" coming because of the virus, hours after the president said the situation was "under control" and that it was a "problem that's going to go away."

On Wednesday evening, Trump told reporters that "there's a chance that it won't spread." In the same press conference, he noted that in California a 15th case of the virus had been confirmed.

But he did not mention what the CDC announced soon after the news conference concluded: that the patient had no known exposure to the virus through travel or close contact with a known infected individual, making it possibly the first case of "community spread" on American soil.

The case raises questions about whether broader testing should be allowed. It appeared to indicate the virus had been circulating among the local community and infecting people, including some who are not sure how or where they became infected, according to the CDC.

Azar had earlier referenced the case at a Wednesday afternoon congressional hearing -- saying its epidemiology was still being discerned -- but he did not provide any details or explain its potential implications.

The federal government has so far resisted wider testing, and Pence's office on Thursday morning did not respond to a question about whether that position had changed considering the California case.

At his Wednesday news conference, Trump even spread misinformation about the virus, incorrectly saying the mortality rate of influenza was higher than that of coronavirus.

While the mortality rate of the coronavirus is not fully understood, this week the World Health Organization posted preliminary findings from within China, pegging the fatality rate of 2 to 4% in the hard-hit city of Wuhan and 0.7% elsewhere in the country. By comparison, the flu's mortality rate is about 0.1%.

Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health (NIAID), speaking next to Pence at the Thursday HHS photo op, also appeared to contradict the president, without mentioning his statement directly, providing an estimate of the coronavirus mortality rate.

"The death rate, or what we call the case fatality rate, is about 2%, 2.5%. Whether that's the most accurate we don't know because it's conceivable that there are enough people who are below the threshold of detecting symptoms, so that the denominator that equation, might be larger. Hence the death rate, maybe less, but even that is a serious case fatality rate because seasonal influenza has a case fatality rate of 0.1%," Fauci said. "Therefore, you have somewhat of a serious potential."

He called it "a serious virus that we're taking very seriously."

Trump's attempt Wednesday to reassure also did not quell economic jitters, with the Dow Jones Industrial Average dropping sharply Thursday for a fourth day in a row.

In a sign the White House had its eye on the economy, the administration on Thursday afternoon that two key economic officials, Treasury Secretary Steven Mnuchin and National Economic Council Director Larry Kudlow, would join the president's coronavirus task force.

U.S. Surgeon General Jerome Adams would also join the group, the announcement from Pence and Azar said.

White House Deputy press secretary Judd Deere told ABC News Thursday that Trump was "receiving regular updates on the coronavirus through meetings and phone calls today," although he did not provide more details, and the president's public schedule did not mention anything related to the virus.

The vice president's office announced Thursday that Pence has appointed a physician to serve in his office as the "White House coronavirus response coordinator." Ambassador Debbie Birx, who has led the U.S. government's efforts to combat HIV/AIDS since 2014, will report to Pence in the new position.

"She has deep experience in coordinating across agencies," Pence's office said in announcing Birx's new role. "She has worked from the research bench to the clinic, but understands the primary focus must always be to reach the individuals most in need. She will bring her infectious disease, immunologic, vaccine research and inter-agency coordinating capacity to this position."

ABC News' Libby Cathey, Katherine Faulders, Anne Flaherty, John Parkinson and John Santucci contributed to this report.