NEW YORK (CBSNewYork) — Twenty million Americans who received Pfizer’s COVID vaccine are now eligible for a booster shot, but approximately 25% of eligible Americans still have not gotten their first dose.

It comes as New York City is still trying to convince some teachers and police officers to get vaccinated. As CBS2’s Christina Fan reported Saturday, New York City Department of Education workers without at least one dose risk losing their jobs.

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Millions of older and vulnerable Americans can now get Pfizer booster shots. Eligible New Yorkers quickly lined up on the Upper West Side.

“It’s the smart thing to do. I don’t know what else to say. It’s following the science,” said Steve Pred.

The CDC recommends boosters for anyone 65 and up, plus those 18 and older with at-risk medical conditions like obesity, diabetes or pregnancy. Front-line workers – including people who work in health care, schools, grocery stores and nursing homes – are eligible too.

The CDC continues to say getting unvaccinated people vaccinated is the number one goal.

“I want to be clear, we will not boost our way out of this pandemic,” said CDC Director Dr. Rochelle Walensky.

Monday was the city’s deadline for public school workers to get at least one shot or risk losing their jobs, but a federal appeals judge temporarily blocked enforcement of the mandate.

The unions said the deadline would trigger staffing shortages.

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“Who the hell said Monday was a good idea? Because that person should be fired,” said Michael Mulgrew, president of the United Federation of Teachers.

Mayor Bill de Blasio said the city is ready for potential shortages.

“We’ve been planning all along. We have a lot of substitutes ready,” de Blasio said.

Scientists say one of the keys to ending the coronavirus pandemic is protecting children. The CDC says schools without mask requirements are 3.5 times more likely to have COVID-19 outbreaks.

Meantime, 39% of the NYPD remains unvaccinated. Eight members are hospitalized in serious condition – some are intubated.

Police Commissioner Dermot Shea is spreading the word about getting the vaccine.

“Make sure that we are doing everything possible to keep each and every one of ourselves safe from this terrible virus,” Shea said.

Federal health officials have not approved booster shots for those who received the Johnson & Johnson or Moderna vaccines.

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CBS2’s Christina Fan contributed to this report.

CBSNewYork Team