Outdoor gatherings of 100 or more to require Green Pass and mask mandate reimplemented for events with 50 or more people, as Omicron pushes case tally above 4,000 for second day

Nachman Ash cites concerns such people more vulnerable to Omicron; mask mandate ordered for large outdoor gatherings; experts warn Bennett of possible jump to 20,000 daily cases

6,000 individuals, including 150 medical staff, to be given additional booster shot in first-of-its-kind research

A third shot of its vaccine 'neutralized the Omicron variant' to levels seen following the second dose, says the pharmaceutical giant in new research

On his way out, De Blasio says no repeat of last year's 'devastating' closure of schools and businesses, even as Omicron variant more than triples infections in 1 week

Government adviser suggests boosters won’t be given to all with weakened immune systems, but would follow data on who is and isn’t retaining protection from the 3rd shot

UN's top immunization official urges well-stocked countries to ease off on booster shots, enabling other countries to get initial doses

Statement comes as top health officials set to hold debate on approving fourth dose for those with compromised immune systems

US follows Israel's lead and places emphasis on those aged 50 and above, urging older populations to get extra shot; expansion makes tens of millions more Americans eligible

Decision still needs CDC approval for Pfizer and Moderna vaccines, with panel to meet later Friday, amid rising cases and fears of a fresh virus wave in winter