Chicago Mayor Lori Lightfoot announced a vaccine mandate for most indoor events as the city grasps with a rise in COVID-19 cases.

Starting Jan. 3, anyone over the age of 5 will have to show proof that they are fully vaccinated to "to dine indoors, visit gyms, or enjoy entertainment venues where food or drink are being served," the mayor's office said in a statement.

Patrons 16 and older will also need to "provide identification that matches their vaccination record," according to the statement.

Chicago is averaging more than 1,700 new COVID-19 cases a day -- a 79% increase from one week ago, the mayor's office said.

Elliot Hospital in New Hampshire is now seeing three to four times as many patients as it had at the beginning of the pandemic, Dr. Laura McPhee told ABC News.

She said their ICU is full with COVID-19 patients and staff is running thin.

"We're tired. It's been extremely hard on everybody," McPhee said, stressing that "most of the patients that we're seeing are unvaccinated."

"Most days I've been angry and frustrated. … Because this is preventable. It doesn't have to happen," she said. "I've not ever seen a patient here in the ICU who has been fully vaccinated with a booster."

-ABC News' Arielle Mitropoulos

About 4,000 nonviolent inmates placed under home confinement due to COVID-19 will not be forced to return to prison at the expiration of the public health emergency, as long as officials determine they have not broken rules and made rehabilitative progress during the period of their release, the Justice Department said.

The announcement follows an extensive review by the Justice Department’s Office of Legal Counsel that for months weighed whether there was any way to keep the inmates placed on home confinement from being forced back into incarceration. An earlier OLC opinion released during the final days of the Trump administration determined they would have to return to prison within a month of the emergency’s expiration.

-ABC News' Alexander Mallin

With omicron now the dominant variant in the U.S., President Joe Biden said in a public address Tuesday, "If you're not fully vaccinated, you have good reason to be concerned."

"The unvaccinated have a significantly higher risk of ending up in a hospital -- or even dying," he said.

Biden said "the unvaccinated are responsible for their own choices" but also blamed "dangerous misinformation on cable TV and social media."

"These companies and personalities are making money by peddling lies and allowing misinformation that can kill their own customers and their own supporters. It's wrong. It's amoral," he said. "I call on the purveyors of these lies and misinformation to stop it."

When reporters confronted the president about people struggling to find tests before the holidays, Biden said omicron "spread even more rapidly than anybody thought."

Biden said the omicron surge created a "big rush" for tests and that this does not resemble a "failure" from the administration.

Biden announced a new plan to distribute 500 million free at-home rapid tests to Americans beginning in January. The free at-home rapid tests will be delivered by mail to Americans who request them. Americans will have to request the tests through a website that will launch in January.

The federal government is also opening more testing sites and mobilizing 1,000 military doctors and nurses to overburdened hospitals.