With a COVID-19 vaccine perhaps just days away in the U.S., most of California headed into another lockdown Sunday because of the surging outbreak and top health officials warned Americans that this is no time to let their guard down.

“The vaccine’s critical,” Dr. Deborah Birx, the White House coronavirus response coordinator, said on NBC’s “Meet the Press.” “But it’s not going to save us from this current surge. Only we can save us from this current surge.”

A Food and Drug administration advisory panel is scheduled to take up a request Thursday to authorize emergency use of Pfizer’s vaccine. Vaccinations could begin just days later, though initial supplies will be rationed, and shots are not expected to become widely available until the spring.

With the U.S. facing what could be a catastrophic winter, top government officials warned Americans anew to wear masks, practice social distancing and follow other basic measures — precautions that President Donald Trump and members of the administration have often disdained.

“I hear community members parroting back those situations — parroting back that masks don’t work, parroting back that we should work towards herd immunity, parroting back that gatherings don’t result in super-spreading events,” Birx said. “And I think our job is to constantly say those are myths, they are wrong and you can see the evidence base.”

The virus is blamed for over 280,000 deaths and more than 14.6 million confirmed infections in the U.S. New cases per day have rocketed to an all-time high of more than 190,000 on average.

Deaths per day have surged to an average of more than 2,160, a level last seen during the dark days in April, when the outbreak was centered around New York. The number of Americans now in the hospital with the coronavirus topped 100,000 for the first time over the past few days.

In California, the first place to enact a statewide lockdown last spring, new stay-at-home orders were set to take effect Sunday night in Southern California, much of the San Francisco Bay area and other areas.

Gov. Gavin Newsom said he hopes the new lockdown order is the last one he has to issue, declaring the vaccine offers “light at the end of the tunnel.”

Once vaccines are offered widely, they could offer long-lasting protection against COVID-19, the head of the U.S. vaccine development effort said. Dr. Moncef Slaoui told CNN’s “State of the Union” that only time will tell for certain but that the vaccine’s effectiveness could last for “many, many years.”

(AP)