With the school year starting next month, time is running out for Colorado teenagers to get fully vaccinated against the coronavirus before returning to class — a move that public health experts said could help maintain in-person learning even with COVID-19 outbreaks.

Colorado’s vaccination rate among teenagers is higher than the national rate, but the state is experiencing a slowdown in overall COVID-19 immunizations and is facing a looming threat from the highly contagious delta variant.

Several Colorado school districts said they will encourage students to get inoculated against the virus, but they stopped short of mandating the shots for the upcoming academic year.

“We really have this critical one- to two-week timeframe where if people are going to get vaccinated, now is the time to do it to get them fully protected in time for school to start,” said Christine Billings, head of the office of pandemic response for Jefferson County Public Health.

About 45% of Coloradans between the ages of 12 and 17 — 200,205 people — have received at least one dose of the vaccine. By comparison, just over 30% of Americans between 12 to 15 have received one dose, according to state and federal data.

In an effort to increase those numbers, the Biden administration this week partnered with pop star Olivia Rodrigo to record videos to encourage more young people to get inoculated.

It’s still unclear what the upcoming school year will look like for Colorado students, although it is likely to be an improvement from the numerous outbreaks and school closures that occurred throughout the 2020-21 academic year.

Mask requirements likely will be relaxed after federal public health officials issued guidance last week advising that vaccinated teachers and students don’t need to wear masks inside schools. State health officials also have said they won’t require students to wear masks, though local districts could require them.

Public health experts also said that fully vaccinated students likely will not have to quarantine and move to remote learning if they are exposed to the virus.

“It is going to be a lot more normal this year, but there are still going to be some health precautions in place,” said Stephanie Faren, director of health services for the Boulder Valley School District, which will announce its mask policy next week.“The truth is we’re still in a pandemic and there are people who still need to be protected. We’re watching it very closely.”

Many school districts in the state aren’t ready to announce the specifics of their plans for the fall — at least not until the Colorado Department of Public Health and Environment releases its guidance for schools.

Jessica Bralish, spokeswoman for the agency, wouldn’t say when the health department will come out with its guidance, saying only that it the agency is “working closely with stakeholders as we prepare for the ’21-’22 school year and prioritize strategies to keep schools safe and uninterrupted in the fall.”

She also didn’t answer a question about whether Colorado will require eligible students to get a COVID-19 vaccine before the school year starts. Instead, Bralish said in an email that the state is focused on increasing access to the shots and providing information about them to Coloradans.

“I feel a lot less isolated”

The 2020-21 school year was filled with uncertainty for students and their teachers. For districts that keep their school buildings open, kids, teachers and staff wore masks and practiced physical distancing, while students were placed in small, tightly controlled groups to curb the spread of the coronavirus.

For some students, such as Ann Marie Vanderveen, remote learning was isolating. Now, she’s preparing to return to in-person classes for her senior year at the Denver School of the Arts.

The 16-year-old got her first dose of the COVID-19 vaccine in April, which she said has allowed her to visit with friends and her grandparents without fear of becoming sick or spreading the virus to loved ones.

“I feel a lot less isolated,” Vanderveen said. “I’ll get to be in-person again, which I’m very excited for. I’m hoping it will feel more like it was pre-pandemic.”

She is now volunteering as a social media content creator for a group called Colorado Teens for Vaccines, which aims to address the state’s low childhood immunization rates.

Denver teens Lily Lemme, 17, and Kate Seneshen,17, started the group, formerly called Denver Teens for Vaccines, in January after finding out about Colorado’s low rate of childhood immunizations.

Most of their outreach is occurring on Instagram, where they share information about COVID-19 vaccines, including advice on how teens can talk to their parents about getting the shot.

“Being in the metro area, most people our age are confident about getting the vaccine. But where we have the block is their parents don’t want them to get the vaccine,” Lemme said. “That’s a pretty significant roadblock.”

Two shots, weeks apart

COVID-19 vaccines are available to anyone 12 and older. But those under 18 need consent from a parent to get immunized against the coronavirus, according to the health department.

A person is considered fully immunized two weeks after they receive their final dose. Pfizer is the only vaccine authorized for teen use, and the second dose of the two-shot regimen can be given between three and six weeks after the first.

That means if someone gets their first Pfizer dose on July 17, the earliest they will be considered fully immunized is mid-to-late August.

Younger people are less likely to have severe COVID-19 than adults, but it’s still possible for them to develop serious cases that can lead to hospitalization or death. They are also at risk of developing what’s known as “long COVID” or a rare — but potentially deadly — inflammatory syndrome condition called MIS-C after a coronavirus infection.

“We just don’t know the long-term effects of COVID-19,” Billings said. “If we can get those kids protected, that’s their best chance of staying in-person in school.”

Colorado is having more primary care doctors, including pediatricians, administer the shots as part of their efforts to reach adolescents, said Dr. Sean O’Leary, a pediatric infectious disease specialist at Children’s Hospital Colorado.

“We know that’s the most trusted source of vaccine information for both patients themselves and for parents,” he said. “The more people we can get vaccinated the fewer cases of COVID we will see.”

Children under 12 are not yet eligible for a COVID-19 vaccine, which both leaves them vulnerable to the virus and means there still will be outbreaks this upcoming school year, said Beth Carlton, an assistant professor of environmental and occupational health at the Colorado School of Public Health.

Since it is possible the virus will be circulating in schools, other measures to reduce transmission — masking, physical distancing and adequate ventilation — will likely still be needed, she said.

What we know (so far) about districts’ plans

Denver Public Schools, the state’s largest school district, isn’t ready to announce its protocols for the fall. But spokesman Will Jones hinted at a more cautious start.

“While we anticipate a return to more normal operations, it is possible that some requirements (such as the use of masks) will continue at the start of the school year,” he wrote in an email.