Pfizer asks FDA to expand emergency use of COVID-19 booster to include 16, 17-year-olds

Omicron variant: What to know about the new COVID-19 strain

An advisory panel of the World Health Organization classified on Nov. 27, 2021, a worrying new COVID-19 variant first detected in South Africa as a highly transmissible virus of concern, naming it "Omicron" under its Greek letter system.

Pfizer-BioNTech asked the U.S. Food and Drug Administration to expand emergency use of its COVID-19 booster dose to include 16 and 17-year-olds, according to a tweet published by the company’s CEO on Nov. 30.

"It is our hope to provide strong protection for as many people as possible, particularly in light of the new variant," Pfizer’s CEO Albert Bourla tweeted.

The request comes as the world rushes to learn more about the new and highly transmissible omicron variant first discovered by South Africa a week ago.

The World Health Organization warned that the global risk from the omicron variant is "very high" based on the early evidence, saying the mutated coronavirus could lead to surges with "severe consequences."

The U.N. health agency’s assessment came as a widening circle of countries around the world reported cases of the variant and moved to slam their doors in an act-now-ask-questions-later approach while scientists race to figure out just how dangerous the mutant version might be.

On Monday, officials from the top COVID-19 vaccine makers say it will take 100 days or less to develop and ship a shot that specifically targets the omicron variant, if needed, amid heightened concern over its spread.

Any omicron-specific vaccine probably could not begin to be produced for another two or three months, Dr. Paul Burton, chief medical officer for Moderna, told the Associated Press on Monday. Burton added that in the interim, getting boosters remains a "very important initial line of defense."

Additionally, Moderna CEO Stephane Bancel said a higher 100-microgram dose of the company’s booster shot could be ready much sooner.

FILE - A woman receives a dose of the Pfizer COVID-19 vaccine at a pop-up clinic offering vaccines and booster shots.

"The higher dose could be done right away but it will be months before the omicron-specific variant is ready to ship in massive quantities," Bancel told CNBC’s "Squawk Box."

President Joe Biden called the new coronavirus variant omicron a cause for concern but "not a cause for panic" and said he was not considering any widespread lockdown. He urged Americans to get fully vaccinated, including booster shots, and return to face masks indoors in public settings to slow any spread.

On Thursday, the Biden administration announced that all travelers to the U.S. must provide proof of a negative COVID-19 test within one day of boarding their flights, regardless of nationality or vaccination status.

The tightening of testing for those entering the country will begin next week and is down from the current three days for those who have been vaccinated.

The new directive is part of Biden’s new winter plan for combating COVID-19 and the new omicron variant, which also includes a requirement for private insurers to cover the cost of at-home COVID-19 tests and paid time off for federal employees to get a booster dose.

"The actions I'm announcing are ones that all Americans can rally behind and should unite us in the fight against COVID-19 and they come from a position of strength," President Joe Biden said in remarks from the National Institutes of Health outside Washington. "We are better positioned than we were a year ago to fight COVID-19."

So far the omicron variant has been detected in three separate cases from three different states: California, Minnesota and Colorado.

All three people who contracted the omicron strain were fully vaccinated, according to state health officials.

Separately, the U.S. Centers for Disease Control and Prevention broadened its recommendation for COVID-19 booster shots to include all adults 18 and older because of the new variant. The agency had previously approved boosters for all adults, but only recommended them for those 50 years and older or living in long-term care settings.

"Everyone ages 18 and older should get a booster shot either when they are six months after their initial Pfizer or Moderna series or two months after their initial J&J vaccine," CDC Director Dr. Rochelle Walensky said in a statement.

WHO said there are "considerable uncertainties" about the omicron variant. But it said preliminary evidence raises the possibility that the variant has mutations that could help it both evade an immune-system response and boost its ability to spread from one person to another.

"Depending on these characteristics, there could be future surges of COVID-19, which could have severe consequences, depending on a number of factors, including where surges may take place," it added. "The overall global risk ... is assessed as very high."

The WHO stressed that while scientists are hunting evidence to better understand this variant, countries should accelerate vaccinations as quickly as possible.

While no deaths linked to omicron have been reported so far, little is known for certain about the variant, including whether it is more contagious, more likely to cause serious illness or more able to evade vaccines. Last week, a WHO advisory panel said it might be more likely to re-infect people who have already had a bout with COVID-19.

Scientists have long warned that the virus will keep finding new ways to exploit weaknesses in the world’s vaccination drive, and its discovery in Africa occurred in a continent where under 7% of the population is vaccinated.

"The emergence of the omicron variant has fulfilled, in a precise way, the predictions of the scientists who warned that the elevated transmission of the virus in areas with limited access to vaccine would speed its evolution," said Dr. Richard Hatchett, head of CEPI, one of the founders of the U.N.-backed global vaccine sharing initiative COVAX.

The Associated Press and Kelly Hayes contributed to this report.