Missouri is preparing to launch a $5 million ad campaign to urge residents to get the coronavirus vaccine as appointment times begin to go unfilled in some places even though the state expanded eligibility to everyone age 16 or older.

Called Stronger Together, the campaign will begin next month and will provide vaccination information through radio, TV, print and social media messages.

"There is definitely misinformation, disinformation circulating," said state health department spokeswoman Lisa Cox. "I think the challenge is very similar to what we saw throughout the last year, making people aware of why these efforts are important and the impact they make and how the virus works and what it is going to take to get back to as close to normal as we feel we can get."

Vaccinators last week reported hundreds of openings for appointments around the state, including in St. Louis, Kansas City, Columbia and Jefferson City, despite the state opening eligibility to anyone 16 or older earlier this month.

"We are hoping that the more education that we can get out that, 'Hey, everyone 16 and up can do this now,' hopefully that will help and cause people to seek out a vaccine," Cox said.

Just 33.3% of Missouri residents had received at least one dose of a COVID-19 vaccine as of Thursday, which is less than half what would be needed to achieve herd immunity.

Cox also said the number of health agencies requesting vaccine doses fell by half the week of April 4 compared to the previous week.

"Some of them do feel like they have really hit a wall as far as who is interested," Cox said, noting the state's vaccine supply did increase substantially last month.

Health officials say it's important to get people vaccinated as soon as possible because, among other reasons, safeguards are being lifted around the state.

The tourist town of Branson did away with its mask mandate as of Friday, and Springfield businesses were allowed to open to full capacity this past weekend.