The Javits Convention Center is now the state's largest vaccine center.

Eligible New Yorkers started getting COVID-19 vaccines there first thing Wednesday morning.

"It went really, really good. Really, safe, no problems whatsoever," one woman said.

The Javits Center was used as a temporary field hospital back in the spring as COVID-19 overwhelmed the city, but now its massive space is being used for a more optimistic purpose.

Those with appointments come in, go through several checkpoints, receive their vaccine at a private table, wait 15 minutes to make sure there's no adverse side effects and then even get to make an appointment for their second dose.

"It worked very well. First they interrogated me, found out what my medical history was, and then I went on and got the shot, which was, I practically didn't notice I was getting it. It was so easy," said 78-year-old Upper East sider Stephen Koch.

But there are some concerns over the supply of the vaccine.

Health officials said the Javits Center has the infrastructure and personnel to administer as many as 25,000 vaccinations a day, but at the moment, because of supply, they anticipate vaccinating just 1,000 people daily.

Officials said, at the current rate of 300,000 doses delivered statewide every week, it could take up to six months just to get through every New Yorker 65 years of age and older, and all of the others eligible to get the vaccine now.

The state is calling on the federal government to buy and release more doses.

"We consider this a wartime mobilization and that lives are on the line every minute of every day. A wartime operation is 24/7, it's an operation that enlists all available allies to get the job done faster," said State Health Commissioner Howard Zucker.

The vaccination site at the Javits Center will be open from 8 A.M. until 6 P.M. every day. Health officials said they would like to expand the hours if they get more resources.

As with other vaccine hubs, appointments are required.