Jill Biden teams up with superheroes to make vaccinations 'comfortable' for kids and their parents

Jill Biden is taking reinforcements with her when she travels to Texas today to promote pediatric vaccines alongside Surgeon General Vivek Murthy: Superman and Wonder Woman.

The first lady and Murthy are scheduled to visit Texas Children's Hospital in Houston, and team up with the comic book legends as part of their effort to encourage parents and guardians to get children ages 5 to 11 vaccinated. Kids who receive their COVID-19 vaccination at a Children's Hospital clinic in November or December will receive bandages featuring DC Comics characters, as well as coloring and activity books -- a collaboration among the White House, DC Comics and WarnerMedia.

As of Wednesday, nearly 1 million kids 5 to 11 had been vaccinated, White House advisers said, a figure they said they're expecting to increase.

"While our program is just fully up and running this week, by then end of the day today we estimate 900,000 kids ages 5 to 11 will have already gotten their first shot -- and through pharmacies alone, 700,000 additional appointments are already on the calendar," Jeff Zients, the White House COVID coordinator, said at a press briefing on Wednesday.

In addition to 20,000 active sites, there are "more coming online, so we expect the pace to continue to accelerate across the coming days and weeks," Zients added. But recent polling suggests that convincing many parents to get their children vaccinated may prove a bit challenging.

While nearly a quarter of parents with kids ages 5 to 11 said they would get their children vaccinated as soon as possible, 38% said they would wait in order to "see if there are any major side effects or problems," according to a recent NBC News poll.

Sunday's appearance marks the second time in recent days Biden has hit the road to tout vaccines to families, with the first lady and surgeon general visiting an elementary school in Virginia just last week.

Karine Jean-Pierre, principal deputy press secretary for the White House, on Tuesday called Biden "a powerful messenger ... really comforting parents if they have questions, or comforting kids."

"She'll be out there more," Jean-Pierre added, "and we're going to continue to try and make sure that parents feel comfortable."