A new COVID-19 mass vaccination site has opened in Suffolk County.

A total of 600 people were vaccinated Wednesday at the Dennison Building in Hauppauge. Officials say there is potential to vaccinate 900 people a day at the location.

It's the third vaccination site run by the county -- along with two at Suffolk Community College campuses in Selden and Riverhead.

Suffolk County said it's been working with organizations and businesses to get better access for those whose jobs put them at greater risk for getting sick.

Suffolk County Executive Steve Bellone says getting vaccine doses is still an issue for the county, but they are expecting more in the coming weeks as supply ramps up in New York.

The announcement comes as Bellone says the county has hit a plateau in terms of the positivity rate, which is hovering around 4% with hospitalizations staying around 400.

"What we've engaged here is a race against the virus, get as many people vaccinated as possible before the virus mutates, as many shots in arms as possible so we can say the virus is behind us," says Bellone.

But some areas -- including much of the Twins Forks -- still don't have any large vaccination sites. That means some East End residents could drive up to an hour to get the shot.

East Hampton Town Supervisor Peter Van Scoyoc says the town created its own distribution site in Wainscott. He praised the county for helping allocate doses, but says more supply is needed.

"We're going to continue providing vaccine as we get it," says Scoyoc. "But every opportunity to increase the amount of vaccine that is distributed throughout our communities is certainly welcome.

There have also been pop-up vaccination events in hard to reach communities. Officials even flew doses to Fisher's Island, a remote community near the Connecticut coast.

HOW TO GET VACCINATED AT DENNISON BUILDING: Call 311 to preregister or preregister online

VACCINE INFORMATION: Check to see if you are eligible

VACCINE TRACKER: Check the latest vaccine statistics from New York