Masks, distancing seen needed post-vaccine

The overwhelming majority of the US population "remains susceptible" to the novel coronavirus, and though most could possibly be vaccinated by mid-2021, wearing masks and social distancing are still necessary, top US health officials said at a hearing Wednesday.

Speaking at a congressional hearing on the US response to the COVID-19 pandemic, Dr Robert Redfield, director of the US Centers for Disease Control and Prevention (CDC), said his agency is in the process of a large sequential study across the country to measure serology.

"The preliminary results on the first round show that a majority of our nation — more than 90 percent of the population — remains susceptible," Redfield said.

The coronavirus has been creating havoc in the country at varying rates, infecting as much as 15 percent to 24 percent of the population in some states and less than 1 percent in others, according to Redfield.

"But it does show that a majority of Americans are still susceptible to this virus," he said.

The hearing came a day after US deaths from the pandemic topped 200,000, with nearly 7 million Americans infected with the virus, more than any other country in the world.

The Institute for Health Metrics and Evaluation at the University of Washington predicted last week that the country's cumulative deaths by Jan 1 would hit 378,320 in a "most likely" scenario that assumes individual mask use and other mitigation measures remain unchanged.

Redfield said that though he had "total confidence" in vaccines, some people may not get protection if they do not develop an immune response.

"What really I was trying to say maybe was just to re-emphasize how important this mask is," he said, holding up a mask at the hearing. "We have this right now, and it will protect the American public."

Last week, Redfield said that "if I don't get an immune response, the vaccine is not going to protect me. This face mask will."

The remarks drew criticism from President Donald Trump, who said Redfield "made a mistake" and insisted that a vaccine is much more effective than the mask.

The CDC chief said that, based on projections, 700 million doses of a vaccine could be ready by late March or April — enough for the country's 350 million population to receive the two shots that are required.

However, he added, "I think that's going to take us to April, May, June, possibly July, to get the entire American public completely vaccinated."

Dr Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said three vaccine candidates have entered into phase three trials and very soon there will be a fourth.

"We feel cautiously optimistic that we will be able to have a safe and effective vaccine, although there is never a guarantee of that," he said. "We predict that sometime by the end of this year, let's say November or December, we will know whether or not these are safe and effective."

Fauci told the Senate hearing that the US could have enough vaccine doses by April. "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," he said.

Fauci cautioned that Americans "absolutely" need to wear masks and stay socially distanced and enforce testing and contact tracing to protect themselves from the virus even after a vaccine becomes available.

"The vaccine availability will go a giant step to controlling the infection, but you're not going to completely eradicate it or eliminate it," he said.

During the hearing, Fauci pushed back against Republican Senator Rand Paul's suggestion that New York is no longer suffering from the pandemic because it achieved herd immunity.

"I challenge that, senator," said Fauci. "This happens with Senator Rand all the time. You are not listening to what the director of the CDC said that in New York it's (an infection rate of) about 22 percent. If you believe 22 percent is herd immunity, I believe you're alone in that."