COVID-19 updates: US daily death average falls below 2,000 for 1st time in month

Asked if Americans should follow the CDC's mask guidance or their state or city's rules, CDC Director Rochelle Walensky said Monday, "We still recommend indoor masking in public settings that have areas of high transmission … and right now that's over 98% of our counties."

But case are "dropping fast," Walensky told Andy Slavitt, former senior adviser to the Biden administration's COVID response team, on his podcast "In the Bubble."

"We are working to update our guidance soon," Walensky said.

-ABC News' Cheyenne Haslett

Carnival has joined Royal Caribbean and Norwegian in easing mask mandates onboard cruises, announcing that masks will be recommended, but not required beginning March 1.

Norwegian previously announced it will drop its mask requirement for vaccinated passengers starting March 1. Royal Caribbean said it will reopen indoor mask-free areas for fully vaccinated travelers on Feb. 14.

-ABC News' Mina Kaji

Moderna said it's in the early stages of research for a combination vaccine that would combine three vaccines into one: a COVID-19 booster, a flu vaccine and an RSV vaccine.

There is no current vaccine against respiratory syncytial virus, known as RSV, a virus that causes mild symptoms in most adults but can be deadly for older adults and young children. This new study will only test the vaccine in adults over 60.

The CDC estimates RSV kills 14,000 Americans over 65 each year.

-ABC News' Sony Salzman

Buckingham Palace on Tuesday canceled some of Queen Elizabeth's virtual engagements, saying the monarch continues to have mild COVID symptoms. 

"As Her Majesty is still experiencing mild cold like symptoms she has decided not to undertake her planned virtual engagements today, but will continue with light duties," palace officials said in a statement.

The palace announced on Sunday that the Queen, 95, tested positive. 

-ABC News' Zoe Magee