Massachusetts Gov. Charlie Baker said he's activating 500 more National Guard members to support the state's strained health care system.

Baker had activated 250 National Guard members when students returned to classrooms in the fall to help with school transportation, ABC Boston affiliate WCVB reported.

In Maine, Gov. Janet Mills is activating up to 169 National Guard members to help overrun hospitals, ABC affiliate WMTW reported. Maine hit a hospitalization record Monday with over 400 COVID-19 patients in hospitals, according to WMTW.

New Orleans will reinstate its indoor mask mandate beginning Wednesday as the city gears up for Mardi Gras celebrations.

Masks will be required in restaurants, bars, gyms, entertainment venues and public transportation.

About 64.6% of New Orleans residents are fully vaccinated, according to the city.

People 5 and older must show proof of vaccination or a negative test to access indoor restaurants, bars, entertainment venues, bowling alleys, indoor playgrounds, arcades and similar settings.

Omicron is estimated to account for 98.3% of new cases in the U.S. as of Jan. 8, according to new data released by CDC Tuesday. (These figures are calculated using modeling and may not be exact.)

Delta now accounts for only 1.7% of new cases nationally, forecasters estimate.

In three areas of the country -- the deep South, the Southeast and the New York/New Jersey region -- omicron is estimated to account for more than 99% of new cases.

In early December, omicron was estimated to account for just 0.6% of all new cases.

-ABC News' Arielle Mitropoulos

The White House has been limiting its in-person gatherings to 30 people "over the last several weeks" due to the omicron surge, White House press secretary Jen Psaki said.

“We wear masks in the West Wing at all times, including in your office, unless you're in your office alone,” Psaki said.

-ABC News' Ben Gittleson

After a bitter two-week debate -- and as a protest was held outside -- the French Parliament voted Sunday to approve legislation that puts a COVID-19 vaccination pass in place. The new law, which will go into effect “around Jan. 20,” will require people aged 16 and over to present a vaccination pass to access public places such as bars, restaurants, cinemas, museums and shopping centers.

The pass will also now be necessary for some forms of transportation, including trains, domestic planes, buses, coaches and carpools. The law specifies that anyone who is not vaccinated must provide a “compelling family or health reason” and a negative test to travel by these modes.

A valid vaccination pass can either contain a full vaccination plan -- which in France consists of three doses -- or a certificate attesting to a recovery from COVID-19 dating back less than six months. COVID-19 screening tests, whether PCR or antigen, will not be sufficient to obtain the pass.

France previously required a health pass for entry to public spaces, but people could keep it valid with a negative test. Young people aged 12 to 15 will still have to present a health pass to enter a place with restricted access.

Business owners can now also request request a proof of identification with a photograph if there are “serious reasons to think that the document presented is not related to the person who presents it.” Those who use a falsified or borrowed pass risk imprisonment and a hefty fine.

-Anna Rabemanantsoa