COVID-19 vaccine interest among Generation Z, those born between 1997 and 2012, has dropped in recent months, according to new polls — a worrying trend as the country opens vaccine eligibility to everyone over age 16.

In a NBCLX/Morning Consult poll conducted last month, 26% of Gen Z respondents said they will not get vaccinated, and 19% said that they do not yet know whether they will. In a similar poll conducted last year, only 5% of Gen Z said that they would not get vaccinated, demonstrating a sharp increase in vaccine hesitancy at a time when other groups are growing more accepting of the vaccine. A recent STAT-Harris Poll also found that 21% of Gen Z respondents said they would not get vaccinated against COVID-19, while 34% said that they would “wait a while and see” before getting vaccinated.

Public health officials are especially concerned about vaccine hesitancy in this age group, as new coronavirus cases have spiked among young adults in a number of states in the last month. New Jersey saw a 31% jump in hospitalizations among young adults ages 20 to 29 last month, said state Health Commissioner Judith Persichilli. Officials are contributing the increase in part to new, more transmissible variants of the virus.

Communication experts say vaccine hesitancy among Gen Z adults may be affected by the dearth of public health messaging on the platforms they use most — social media. Continued emphasis in the media on the vulnerability of older people also plays a part.

Allyson Levin, a visiting assistant professor at Villanova University who studies mass communication, said hesitancy among Gen Z does not surprise her, given that young people have not received clear and consistent messaging around vaccines as much as some other groups.

“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,” Levin said. “Messages should be scientifically accurate and evidence-based.” However, she noted that some videos on social media platforms share misinformation, which “could have the potential to undermine other public health and communication efforts.”

For most of the pandemic, messages in the media reinforced the idea that real vulnerability to the virus is tied to being older, said Kathleen Hall Jamieson, director of the University of Pennsylvania’s Annenberg Public Policy Center. From the beginning, there has been a lot of imagery emphasizing the vulnerability older people have to the virus, such as photos of nursing homes, she said.

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“There was less concern about other generations until very recently, which has started to create problems,” Jamieson said. “If you haven’t been paying attention to the media recently, how vulnerable would you think you were if you were in the younger generations? The answer is not very.”

Complicating factors is the country’s successful push to get high school and college students back into schools, meaning many young people did not see themselves as “the focus of anxiety,” Jamieson said. Plus, the vaccine was not available to younger generations until very recently, so it’s possible that they rationalized not getting it in the meantime, she said.

But there are signs that recent messaging is shifting for young people, Jamieson noted. There is now clear evidence that exposure to the virus, even if it doesn’t result in hospitalization, can have serious long-term consequences.

“As there is clearer evidence about how this virus has a longer term effect on people, and those effects are not small ones, they’re serious, that’s changing the signal for younger people,” she said.

One of the ways medical professionals are trying to encourage Gen Z to get vaccinated is by posting public health information from the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) on TikTok, Levin said.

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

On social media platforms such as TikTok, young people are often looking for authenticity and people they can trust, Levin said. That’s why medical professionals who share public health information on social media often communicate their credibility by wearing their white coats, talking openly about their training, or creating content from their offices. They also often respond to questions in the comments, she said.

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“Part of what these doctors are doing is making science understandable for the public,” Levin said. “Some of these videos average a quarter million views, and they’re not just about COVID … It’s great because users and Gen Zers can just scroll through feeds and come across these messages, which meet them where they already are.”

Afrah Howlader, a 21-year-old senior studying public health at Drexel University, said she’s seen lots of TikTok videos about the vaccine in the last few months. She’s noticed scientists posting videos trying to dispel myths that the vaccines are not safe because of how quickly they were made, as well as videos explaining why the Johnson & Johnson vaccine was paused and why that shouldn’t cause significant worry for most.

“I personally love them because they’re disseminating science to a larger population, making it more accessible and easier to understand,” Howlader said. “I’ve also seen a lot of jokes about the vaccine but mainly about how excited and the lengths [people] are willing to go to in order to get the vaccine.”

Howlader noted that while most of the messaging she’s seen has been positive and credible, the app’s For You page, a curated feed based on what the user engages with, can be an “echo chamber.”

“I know the bad ones are out there though,” Howlader said. “[Which] makes me kind of nervous since young people are so impressionable.”

Austin Chiang, chief medical social media officer and director of the endoscopic bariatric program at Jefferson Health, has been sharing public health information on TikTok since 2019. At first he was just curious about the new social media platform, but soon realized that he could “put [his] own health twist on some of the trends and dances,” Chiang said. Today, he has nearly 400,000 followers.

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“When the pandemic hit, all eyes were on health professionals, especially early last year,” Chiang said. “Everyone was looking for COVID information. I was livestreaming several times a week to answer questions.”

The hype has simmered down a little since then, Chiang said, but he still regularly posts videos about new CDC guidelines. In January, he made a video using a popular dance trend to update followers on his reaction to the second dose of the COVID-19 vaccine and explain that the symptoms he experienced meant his immune system was working.

“People have short attention spans, including myself,” Chiang said. “When I make videos, I always think, ‘Is this something I would find funny or interesting?’ ”

Chiang said he tries to engage with commenters who display a genuine curiosity. When his comments show a lot of anti-vaccine sentiment, he’s less likely to respond.

“I don’t want things to become really contentious,” Chiang said. “When things turn ugly, it further erodes trust in health care because we become heated and emotional in our conversations.”

Jamieson said she’s not concerned about Gen Z’s vaccine hesitancy lasting for a long time, as many young people may change their minds in coming weeks. Some of the hesitancy, she said, may be related to the fact that the pharmaceutical companies manufacturing the vaccines have not yet concluded vaccine trials for adolescents and teenagers.

“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.”