International travellers wait to take PCR tests upon arriving at the OR Tambo International airport in Johannesburg, Nov 27, 2021. One nation after another shut its doors to southern Africa over the weekend, even as they spurned public health measures that scientists said were far more urgently needed to take on the omicron variant of COVID. (Joao Silva/The New York Times)

Top federal health officials in the United States urged unvaccinated Americans on Sunday to get their shots and for eligible adults to seek out boosters, amid the discovery of a new variant.

Appearing on several morning talk shows Sunday, Dr Francis Collins, director of the National Institutes of Health, cautioned Americans that the emergence of omicron and the uncertainty that surrounds it is a reminder that the pandemic is far from over. While the variant has yet to be detected in the US, maintaining vigilance and safeguarding public health through inoculations, masking indoors and distancing, remains critical, he said.

“I know, America, you’re really tired about hearing those things, but the virus is not tired of us,” Collins said. “And it’s shape-shifting itself.”

President Joe Biden will give an update on the US response to the variant Monday, the White House said in a statement Sunday evening after he met with Collins and Dr Anthony Fauci, the nation’s top infectious disease expert.

Currently, much remains unknown about the omicron variant, which has a concerning number of mutations not seen before. It is unclear whether it causes severe illness or is more transmissible than previous variants. There are also questions around whether omicron limits vaccine’s effectiveness.

Still, Collins stressed that inoculation remains the first line of defense, saying that there are “good reasons” to believe, based on previous variants, that current vaccines will provide sufficient protection.

“Please, Americans, if you’re one of those folks who’s sort of waiting to see, this would be a great time to sign up, get your booster,” Collins said on Fox. “Or if you haven’t been vaccinated already, get started.”

He also underlined other critical mitigation efforts, including indoor masking when around unvaccinated individuals and maintaining social distance, in slowing the spread.

Fauci delivered a similar message, sending a “clarion call” for vaccinations and boosters. It is inevitable that the variant, which has already been detected in several countries, will surface in the US, Fauci said.

“The question is, will we be prepared for it?” Fauci said on ABC’s “This Week” on Sunday morning. “And the preparation that we have ongoing for what we’re doing now with the delta variant just needs to be revved up.”

The discovery of the omicron variant stoked widespread fear and alarm, and governments around the world announced border closures to travelers from South Africa and several neighboring countries.

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