The Best Birthday Present in 2021? A Covid Vaccine.

But parents are now navigating a tricky moment in which some children are vaccinated while many others, who are under 12, are not. Some parents, including Ms. Tu, are for the most part limiting their children to indoor play dates with vaccinated friends.

After Zoe got the shot, her mother posted on Instagram to mark the moment: “Turning 12 in 2021 means a different kind of celebration,” Ms. Tu wrote, with syringe and birthday cake emojis.

Zoe’s vaccination was a milestone moment for her parents, too. “On her birthday we’re one step closer to being safer because our whole family can be vaccinated,” Ms. Tu added. “It’s a new chapter for us.”

For some young people, getting vaccinated adds poignancy to a birthday. Many spent the past year isolated from friends, yearning for normalcy and confining their friendships primarily to phones and computers.

Several studies have shown deteriorating mental health, including bouts of anxiety and depression, among teenagers during the pandemic. Getting a Covid vaccine offers some teenagers a glimmer of promise for more socializing.

Some students did not want needles to mar their actual birthdays. Sebastian Holst, 12, of Brooklyn, was relieved that his parents had scheduled his vaccine appointment for several days after his birthday in May. That way, he was able to hold a Zoom birthday party with friends, take a walk with his mom and enjoy his dad’s tacos, free of worry about any possible side effects.

“Getting vaccines doesn’t feel great, but I know I have to, so I suck it up,” he said.

Heading to the Javits Center in Manhattan later that week for his shot brought a burst of excitement as he envisioned a new school year that might improve over last year’s. Sebastian’s school offered a blend of in-person and remote learning last year, and on the days when he was remote, he missed bumping into friends in the hallways. And remote classes via Zoom eliminated the separation between home and school, he said.