Supreme Court Justice Stephen Breyer plans to retire, giving President Joe Biden a chance to nominate to the bench, a well-placed source familiar with the matter told CNN.

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The US and a handful of allies are in discussions to deploy thousands more troops to Eastern European NATO countries, before any potential Russian invasion of Ukraine as a show of support in the face of Moscow's ongoing aggression, three US officials familiar with the discussions tell CNN.

The deployments -- numbering approximately 1,000 personnel from each -- would be similar to the forward battle groups currently stationed in the Baltic States and Poland, two defense officials said.

Among the countries considering accepting the deployments are Romania, Bulgaria and Hungary, all three officials said.

No final decisions have been made.

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The second New York Police Department Officer shot while responding to a domestic incident in Harlem last week has died, according to the commissioner for the department.

"It's with great sadness I announce the passing of Police Officer Wilbert Mora," NYPD Commissioner Keechant Sewell tweeted via verified social media.

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Pfizer and BioNTech have begun a clinical trial for their Omicron-specific Covid-19 vaccine candidate, they announced in a news release on Tuesday.

The study will evaluate the vaccine for safety, tolerability and the level of immune response, as both a primary series and a booster dose, in up to 1,420 healthy adults ages 18 to 55.

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A state supreme court judge struck down New York state's mask mandate Monday, ruling that the governor and NY State Department of Health did not have the authority to enact such a mandate without approval from the State Legislature.

In an opinion released Monday, Nassau County Supreme Court Judge Thomas Rademaker argued that because New York was no longer under a state of emergency at the time the mask mandate was announced, the governor and health commissioner did not have the additional authority to order such a mandate, adding the mandate is now unenforceable.

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