ANNAPOLIS, Md. (AP) — Demand for COVID-19 vaccine in Maryland remains high, but Gov. Larry Hogan said Wednesday the state is needing to get more creative to use all of its vaccine supply.

Maryland has administered more than 4 million vaccines, the governor said. More than 82% of people over 65 have been vaccinated, and more than 55% of people over 18 have been vaccinated.

“We truly are close to that light at the end of the tunnel, but those of you who have not yet been vaccinated please go get a vaccine as quickly as you can," Hogan said.

To better reach others, Hogan announced initiatives to better get shots into the arms of the unvaccinated. He's calling it “No Arm Left Behind,” and it will involve all state agencies and private companies.

“This will include redoubling our efforts to reach that remaining 18% of Maryland seniors by going county by county and zip code by zip code in an effort to get every senior vaccinated," Hogan said at a news conference.

The effort will include reaching out directly to more than 70,000 of the state's Medicaid recipients who have not received a vaccine.

State health officials also are partnering with some of the largest employers in Maryland, including Southwest Airlines, Exelon, Comcast, Amazon, and others to get their workforces vaccinated as expeditiously as possible.

The state is opening its newest mass vaccination site at Ripken Stadium in Harford County on Thursday. The state's 13th mass vaccination site will open in Columbia next week.

Hogan said more no-appointment walkup lines are being opened at mass vaccination sites as well, including in Annapolis at the Navy-Marine Corps Stadium, the Baltimore Convention Center and a site in Greenbelt supported by the Federal Emergency Management Agency. Walkup lines are being expanded at M&T Bank Stadium in Baltimore and the sites in western Maryland and on the Eastern Shore.

The state also is encouraging everyone at Maryland colleges to get vaccinated. The state's vaccine equity task force is expanding use of mobile clinics to vaccinate people in hard-to-reach areas.

Hogan said the state is continuing to get shots into arms, "but we’re having to do lots of creative things to get the same number of vaccines done every day.”

The state's mass vaccination sites sometimes experience a drop off in people who schedule appointments and actually show up, because they are able to get a shot somewhere else before their appointment. That's why the walkup lines are being expanded.

“You can’t plan for how many people are going to show up,” Hogan said. “You can’t know exactly who’s not going to make it to their appointment, but so far we haven’t dropped off at all.”

Hogan said Maryland is enhancing the capabilities of its state call center to answer questions and book appointments for mass vaccination sites. It will providing direct assistance to people who need help getting a vaccine, particularly those who are homebound or who need transportation or technological assistance, he said.

It will be available seven-days-a-week from 7 a.m. to 10 p.m. by dialing 1-855-634-6829.