During a news briefing, the governor said that's ahead of the initial goal of May 1.
"Given the trajectory we are on, we believe this is the right time to put our program into higher gear," he said.
That decision comes as New Jersey leads the nation in cases per capita over the past week with 351 cases per 100,000 people.
BREAKING: Effective April 19th, all New Jerseyans age 16+ will be eligible for vaccination. pic.twitter.com/SxebbSRjNn— Governor Phil Murphy (@GovMurphy) April 5, 2021
Residents 16 and over with intellectual and developmental disabilities are eligible for the vaccine right now.
Also eligible as of Monday are all residents age 55 and up, as well as additional frontline essential workers, which includes those working in higher education.
Nearly 1.8 million people have been fully vaccinated in New Jersey. Murphy said that the state is "38% to our goal of 4.7 million fully vaccinated adults by June 30th."
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New Jersey officials said more than 700 vaccination centers have been opened in the state.
Murphy also announced Monday that fully vaccinated people who travel domestically are no longer required to self-quarantine after their trip or get tested before or after travel.