Editor's note: This story was updated on May 7, 2021.

Millennials and Gen Zers are increasingly hesitant to get vaccinated against Covid-19, but officials say there's a way to reach young adults with public health messaging tailored to their concerns and questions.

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Vaccine hesitancy is higher among millennials and Gen Z than older adults

According to a NBCLX/Morning Consult poll conducted in March 2021, Generation Z (ages 18-23) and millennial (ages 24-34) adults are now the generations most likely to say they are not planning to get vaccinated or are unsure whether they'll get vaccinated. Specifically, the poll found 23% of adults between 18 and 34 said they will not get vaccinated, including 26% of respondents between the ages of 18 and 23. In addition, 21% of Gen Z and millennial respondents said they haven't decided whether they want to get vaccinated.

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Similarly, a poll conducted by STAT News and The Harris Poll found that 21% of Gen Z adults said they would not get vaccinated, while another 34% said they would take a "wait awhile and see" approach before making up their mind either way.

The latest survey data "represents a steep increase in vaccine hesitancy from March 2020," when a similar poll conducted by NBCLX and Morning Consult found only 10% of respondents between the ages of 18 and 29 said they wouldn't get vaccinated, and 15% of respondents in that age group said they didn't know whether they would get vaccinated, NBCLX reports.

Why younger adults are hesitant

According to Kathleen Hall Jamieson, director of the Annenberg Public Policy Center at University of Pennsylvania, one reason younger adults may be hesitant about the vaccines is because most public messaging has focused on the coronavirus's threat to older adults, who typically are susceptible to more severe cases of Covid-19 than younger adults.

As a result, many young adults may be less worried about ending up in the hospital than older adults because, although there's a possibility they may experience long-term Covid-19, some young adults have already recovered from mild cases of Covid-19 or they've seen their friends get better after being infected, Bloomberg reports.

"We are hearing from folks that they are not worried about the vaccine, or it's more important for their grandparents to get vaccinated, or they don't know where to get vaccinated, they don't know when they'll be able to get vaccinated," Justin Atkins, national politics manager at the nonprofit NextGen America, said. "We have young folks [who] still believe they can't get vaccinated because it's something that's reserved only for the elderly."

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Other experts said the issue was not just the content of the public health messaging, but the platforms on which such information was shared. For instance, communication experts say a lack of public messaging about Covid-19 vaccines on social media may be contributing to the vaccine hesitancy among young adults, the Philadelphia Inquirer reports.

There are also other reasons younger adults may be declining to get vaccinated, Parth Patel, lead author of the UCL Virus Watch paper, said, such as having to take time off work or school to get vaccinated, or having to travel long distances.

How to combat vaccine hesitancy among young adults

Public health experts interviewed by STAT News said vaccine hesitancy among young adults can be resolved with a coordinated communications campaign designed to deliver reliable and useful information that will make it easier and more enticing for young adults to get vaccinated.

For instance, Allyson Levin, a visiting assistant professor at Villanova University who studies mass communication, said health care providers are now using TikTok to share public health information from CDC and the World Health Organization to encourage young adults to get vaccinated.

"They're sharing evidence-based facts in a way … that Gen Z can understand, with the dancing and colorful images," Levin said. "They're using storytelling in a way that makes complex scientific information digestible."

For example, Austin Chiang, chief medical social media officer and director of the endoscopic bariatric program at Jefferson Health, who has been using TikTok to share public health information since 2019, said, "When the pandemic hit, all eyes were on health professionals, especially early last year. Everyone was looking for [Covid-19] information. I was livestreaming [on TikTok] several times a week to answer questions." Then in January, Chiang made a TikTok video explaining his body's immune response to a Covid-19 vaccine dose, the Inquirer reports.

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Levin said, "Effective messaging for Gen Zers on TikTok … looks a lot like effective health messaging elsewhere in so-called legacy media formats, such as newspapers or television. Messages should be scientifically accurate and evidence-based."

In other efforts, CDC last month announced a $3 billion initiative intended to increase vaccine acceptance—and the Biden administration launched a public relations campaign that features a coalition of several hundred groups to spread positive messages about Covid-19 vaccines. One coalition member, NextGen America, plans to send text alerts and emails to one million young adults to answer basic questions about the vaccines and help them figure out where to get vaccinated, STAT News reports.

And some officials are leaning on colleges and universities, which—when students return to campus—are uniquely able to influence younger adults' willingness to get vaccinated by sharing positive messaging, establishing convenient vaccination sites, or even by mandating vaccination for students. "We know how to reach different parts of our students with the messages they need," said Sarah Van Orman, division chief of college health at the University of Southern California.

Younger adults are also taking matters into their own hands, STAT News reports, with several young influencers sharing positive vaccine messaging on their platforms. For instance, Jordan Tralins, a 19-year-old student at Cornell University launched the Covid Campus Coalition, a campaign that posts university-themed infographics addressing common vaccine questions on Instagram.

"I hadn't seen any type of campaign targeted toward people my age … and that's how the idea came to be," Tralins said.

For her part, Jamieson said she's not worried vaccine hesitancy among young adults will last for a long time, as she expects many young adults will change their minds over the next few weeks, especially once new clinical trial data on the vaccines' effectiveness among adolescents becomes available.

"Someone might be looking at the situation and think, 'I'm much closer to 18 than I am to 65, I might want to wait until I've seen the studies for 12- to 18-year-olds,'" she said. "It doesn't necessarily suggest that you have a population avoiding vaccines for bad reasons."

And there's data to suggest young adults will likely change their mind. For example, one study found that among those who indicated they wouldn't get vaccinated or they were unsure about getting vaccinated in December 2020, 86% said they would be open to getting vaccinated in February 2021 (Williams, Bloomberg, 4/21; Ao, Philadelphia Inquirer, 4/19; Pransky, NBCLX, 3/24; Florko, STAT News, 4/8).