CHICAGO (NewsNation Now) — The rise in COVID-19 infections in children is raising concerns about a potential surge of variants in the United States.

“If you look at what’s happening in Michigan and Minnesota and Massachusetts, for example, you’re seeing outbreaks in schools and infections in social cohorts that haven’t been exposed to the virus before,” Dr. Scott Gottlieb said on CBS’ Face the Nation Sunday. “Maybe we’re doing a better job sheltering. Now they’re out and about getting exposed to the virus and they’re getting infected. So the infection is changing its contours in terms of who’s being stricken by it right now.”

In earlier surges, children played a minor role in transmitting the virus, and if they were diagnosed with COVID-19, the majority only had mild symptoms. This new development has some raising questions. 

“I think the schools can be made more safe,” said Gottlieb. And I think the benefits of being in school outweigh the risks. But we need to be cognizant of the fact that schools are a risk factor. Children are vulnerable to the infection, and that the schools can become focal points for community spread if we’re not careful.

Also this weekend, a new vaccine record reported by the Centers for Disease Control and Prevention, with more than 4 million doses were given in a 24-hour period. This brings the 7-day average to more than 3 million per day. 

But with each triumph, more challenges.

Federal officials worry about public confidence in the vaccine. A mix-up at a Baltimore facility resulted in 15 million spoiled doses. The Biden administration put Johnson & Johnson in charge of that plant. It was manufacturing both the Johnson & Johnson and AstraZeneca vaccines and mixed up the ingredients.

This as several states report a rise in cases, including concentrations in the Midwest, Northeast and Florida. One potential reason for the spike: people taking vacations for spring break, or to celebrate Easter and Passover.

The Transportation Security Administration reported more than 1.4 million people passed through airport checkpoints across the country Saturday. Last year, that figure was just over 118,000.

Meanwhile, the CDC is offering mixed messages about travel — advising people to stay home for Easter and to remain socially distant. At the same time, saying Americans who are fully vaccinated should feel safe to travel. 

But other health experts caution the pandemic isn’t over yet and no vaccine is 100% effective.

“When you get vaccinated, it’s like buying a fireproof suit that works 90 to 95% of the time. But it doesn’t work all the time. So why want to walk into a big fire if you don’t have to,” epidemiologist Michael Osterholm said on NBC’s Meet the Press Sunday.

The CDC has cleared the way for Americans for domestic and international travel, as well. This despite the fact that several countries including, France and Italy, have imposed new lockdowns as cases and new variants are on the rise.

“We really are in a category five hurricane status with regard to the rest of the world,” said Osterholm. “At this point, we will see in the next two weeks the highest number of cases reported globally since the beginning of the pandemic. In terms of the United States, we’re just at the beginning of this surge.”