COVID-19 "is one of the top ten leading causes of death in children" and vaccines are a "safe and simple intervention" to significantly lower the risk of severe illness, emergency physician Dr. Leana Wen and professor of health policy and management at GW said at a National Press Foundation briefing Wednesday.

Dr. Sean O’Leary, vice chair of the committee on infectious diseases for the American Academy of Pediatrics, said he believes that the fear surrounding the vaccine is largely based on misinformation.

Both doctors also pointed to the problem of access to vaccines, with many Americans in rural areas living in “pharmacy deserts.”

“We should not assume that these people don’t want the vaccine. A lot of it is access,” Leary said.

Officials need to hold clinics in places like schools, Wen added.

-ABC News' Arielle Mitropoulos

Disney Cruise Line said it will require all passengers ages 5 and up to be fully vaccinated against COVID-19 starting next year.

Guests who are not vaccine-eligible because of their age will have to provide proof of a negative COVID-19 test result taken between three days and 24 hours their sail date.

"We are resuming sailing in a gradual, phased approach that emphasizes multiple layers of health and safety measures, considering guidance from the U.S. Centers for Disease Control and Prevention and other medical experts," Disney Cruise Line said Wednesday in an updated policy on its website. "Under this guidance, we’ve reimagined your cruise experience so we all can enjoy the magic responsibly."

The vaccine mandate will take effect Jan. 13 and will apply to sailings both in the United States and abroad.

Currently, passengers ages 12 and older as well as all crew members must be fully vaccinated, while unvaccinated guests ages 5 to 11 must take a pre-departure COVID-19 test.

The Food and Drug Administration is expected to authorize Pfizer's and Moderna's COVID-19 booster doses for all adults as soon as Thursday, a government official with direct knowledge of the process told ABC News.

That would come in time for the Centers for Disease Control and Prevention's advisory panel meeting this Friday to discuss booster recommendations regarding all adults for both manufacturers.

The CDC previously signed off on a third dose of both vaccines for certain populations, as well as a booster of the single-dose Johnson & Johnson vaccine for anyone 18 years and older.

-ABC News' Eric Strauss

Moderna has now asked the FDA to authorize its COVID-19 booster for all adults.

Pfizer has already asked the FDA to amend its booster authorization to all adults.

The FDA could make an authorization decision by Friday. The CDC also needs to sign off. The CDC's advisory committee will meet on Friday to discuss new booster recommendations.

Johnson & Johnson boosters are already authorized for everyone 18 and older.

-ABC News' Sony Salzman

The daily case average in the U.S. now stands at 78,500 – a 23% jump over the last 2.5 weeks, according to federal data

Twenty-one states have seen an uptick in daily cases of 10% or more over the last two weeks: Arizona, Arkansas, Connecticut, Illinois, Indiana, Iowa, Kansas, Massachusetts, Michigan, Minnesota, Missouri, Nebraska, Nevada, New Hampshire, New Mexico, New York, Ohio, Pennsylvania, Rhode Island, Vermont and Wisconsin.

Last week marked the first national increase in hospitalizations in nearly 10 weeks. There are now more than 47,000 patients with COVID-19 in hospitals -- up by about 2,000 patients since last Monday, according to federal data.

-ABC News' Arielle Mitropoulos