• Fauci again contradicted President Trump's timeline for when a vaccine will be widely available, saying it should be by April
  • Janssen Pharmaceutical Cos. opened the largest phase 3 clinical trial yet of a coronavirus vaccine
  • The head of the FDA said any decision on a vaccine will be driven by science, not politics

Dr. Anthony Fauci, the nation’s leading infectious disease expert, testified Wednesday there is growing optimism among scientists that a safe and effective vaccine for coronavirus is on the horizon, and chastised Sen. Rand Paul for misstating but it is unlikely one will be available by the end of October as President Trump has insisted.

The testimony came as the largest phase 3 clinical trial yet got underway and as the Food and Drug Administration considered tightening its standards for approving an emergency use authorization for any vaccine to help shore up public confidence in the approval process and allay fears the process had been politicized.

U.S. COVID-19 deaths topped 201,000 Wednesday.

Also testifying Wednesday before the Senate Health, Education, Labor and Pensions Committee were FDA head Stephen Hahn, who pledged any decision on a vaccine would be driven by science and not politics, and Dr. Robert Redfield, head of the Centers for Disease Control and Prevention, who testified 90% of the U.S. population remains vulnerable to COVID-19.

"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.

Fauci said the U.S. should have 700 million doses of vaccine available by April.

“In November there’ll probably be maybe 50 million doses available. By December maybe another 100-plus million. And then you get into January and February. By the time you get to April, it’ll be a total of about 700 million,” Fauci said in prepared remarks. “They will be rolling in as the months go by and by the time you get to maybe the third or fourth month of 2021, then you’ll have doses for everyone.”

Fauci got into a testy exchange with Paul, R-Ky., who has frequently criticized lockdowns and public health measures for mitigating the virus’ spread. He told Paul he was misstating the extent of immunity from the virus in New York City, where it is believed 22% of the population had contracted the disease and which has brought down its test positivity rate to 1%. Paul attributed the low positivity rate to herd immunity.

"You are not listening to what the director of the CDC said, that in New York [the infection rate is] about 22 percent. If you believe 22 percent is herd immunity, I believe you're alone in that," Fauci said. It is generally accepted that at least 80% of the population would have to be immune from a contagion before it ceased to be a factor.

Fauci also knocked down Paul’s assertion that exposure to other coronaviruses had provided some people with at least partial immunity.

Fauci, saying a vaccine is essential, noted Moderna, Pfizer, AstraZeneca and Johnson & Johnson all have vaccine candidates in phase 3 clinical trials. Novavax is expected to initiate a late-stage trial next month.

The J&J trial is the largest, enrolling as many as 60,000 volunteers at 215 clinical research sites. The vaccine was developed by J&J’s Janssen Pharmaceutical Cos.

“The Janssen candidate has showed promise in early-stage testing and may be especially useful in controlling the pandemic if shown to be protective after a single dose,” Fauci said.

The vaccine candidate also does not require the extreme cold temperatures for storage as do the other candidates.

Preclinical findings in rhesus monkeys indicated the vaccine could provide near complete protection and interim results for humans indicated it is safe and prompts an immune response.