The Centers for Disease Control and Prevention said Tuesday it is working to change its international travel guidelines to require COVID-19 testing one day before departure to the U.S. in light of the omicron variant.

"CDC is working to modify the current Global Testing Order for travel as we learn more about the Omicron variant; a revised order would shorten the timeline for required testing for all international air travelers to one day before departure to the United States," the CDC said in a statement. "This strengthens already robust protocols in place for international travel, including requirements for foreign travelers to be fully vaccinated."

The CDC continues to recommend that all travelers get a COVID-19 viral test three to five days after arrival in the U.S. and that unvaccinated travelers quarantine for seven days even if they test negative.

-ABC News' Cheyenne Haslett

Pfizer has officially requested Food and Drug Administration authorization of its COVID-19 booster for 16- and 17-year-olds, the company's CEO said Tuesday evening.

"It is our hope to provide strong protection for as many people as possible, particularly in light of the new variant," Albert Bourla tweeted, referring to omicron, a recently discovered variant of concern, according to the World Health Organization.

-ABC News' Sony Salzman

Nearly 132,000 children tested positive for COVID-19 last week, as pediatric cases remain "extremely high." according to a new report from the American Academy of Pediatrics and the Children’s Hospital Association.

This marks the 16th consecutive week that weekly pediatric COVID-19 cases have been above 100,000. Prior to the recent increases, infections among children had been steadily dropping since the pandemic peak of 252,000 child cases, recorded over the span of a week in early September.

At this time, severe illness due to COVID-19 remains "uncommon" among children, the two organizations wrote in the report. However, they warn that there is an urgent need to collect more data on the long-term consequences of the pandemic on children.

The latest report comes amid growing concerns surrounding the new omicron variant, launching a renewed push to get all eligible Americans vaccinated against COVID-19. To date, about 36% of children ages 5 to 17 have received at least one dose, according to federal data.

-ABC News' Arielle Mitropoulos

Advisers from the U.S. Food and Drug Administration have narrowly approved an endorsement of the Merck COVID-19 pill, voting 13 to 10 in favor of the authorization.

If authorized, it would be the first easy-to-take antiviral pill for COVID-19. Pfizer is also working on a COVID-19 pill, which it hopes will be authorized early next year. The FDA typically takes the advice of its advisers but will make its own final decision.

During Tuesday’s meeting, advisers spoke positively on Merck's pill, even though it was not found to be quite as effective in the final analysis as it was in an early, preliminary analysis.

However, the advisers expressed doubt about whether it would be safe for pregnant people to use Merck's pill because of the potential risk of harm to the fetus as well as its use in children due to lack of data and similar concerns as in pregnancy.

-ABC News' Sony Salzman

At least 10 people have tested positive for COVID-19 on a Cruise Norwegian ship disembarking in New Orleans this weekend, according to the Louisiana Department of Health.

Those infected include both passengers and crew members, officials said.

The Norwegian Breakaway departed from New Orleans on Nov. 28 and stopped in Belize, Honduras and Mexico on its voyage. There are more than 3,200 individuals on board, the health department said.

The company required on-site testing in addition to proof of vaccination before boarding the vessel, according to the Port of New Orleans.

The health department said the cruise line has been adhering to appropriate quarantine and isolation protocols. In addition, everyone aboard the ship will be tested for COVID prior to disembarking.

Those who test positive for COVID-19 on the ship will either travel by personal vehicle directly to their private residence or self-isolate according to current Centers fo Disease Control and Prevention guidelines in accommodations provided by Norwegian Cruise Lines.

"The health and safety of our guests, crew and the communities we visit is our highest priority, and we will continue to take all appropriate actions to ensure their wellbeing and protect public health," a Norwegian Cruise Lines spokesperson told ABC News.

"We have identified a handful of COVID-19 cases among guests and crew onboard Norwegian Breakaway, which is scheduled to disembark in New Orleans, LA on December 5. All of the identified cases onboard are asymptomatic. In addition to requiring that 100% of guests and crew are fully vaccinated, per the Company's comprehensive health and safety protocols, we have implemented quarantine, isolation and contact tracing procedures for identified cases."

The spokesperson said the company is testing all individuals prior to disembarkation, and providing post-exposure and quarantine public health guidance by the CDC.

"Any guests who have tested positive for COVID-19 will travel by personal vehicle to their personal residence or self-isolate in accommodations provided by the Company according to CDC guidelines," the spokesperson said. "We take this matter extremely seriously and will continue to work closely with the CDC, the office of Governor John Bel Edwards, the Louisiana Department of Health as well as the city and port of New Orleans. At this time, there have been no changes to scheduled future sailings on Norwegian Breakaway. We will provide additional updates to impacted guests as appropriate."