Why COVID infection rates in kids are on the rise in some states, but not others

Kids wear face masks
Kids wear face masks while adults remain unmasked in Ohio. (Gaelen Morse/Reuters) (Gaelen Morse / reuters)

COVID-19 infections are on the rise, including in children, in many areas across the country. While children under the age of 12 aren't authorized to receive the COVID-19 vaccine anywhere in the U.S., certain states are seeing surges of cases in this age group compared to other states.

Dr. Ashish Kumar Jha, dean of the Brown University School of Public Health, broke it all down in a Twitter thread that’s gone viral. “While vaccination rates for kids under 12 are identical (0%) across states, infection numbers are not,” he wrote. “In Massachusetts, about 250 kids under 10 years of age infected last week. In Florida, it was about 9,000. In Louisiana, it was about 1,600.”

"Florida had 12X as many kids infected as Massachusetts last week," he continued. "And Louisiana? About 10X. So what's going on? None of these kids are vaccinated! So why are infection rates so much lower in MA? Right, because kids are protected by adults.”

Arkansas Gov. Asa Hutchinson is also urging parents to protect their children, noting that as of Thursday there were 24 children in the state who were hospitalized with COVID-19, and none were fully immunized, per KUAR, an NPR affiliate in Little Rock, Ark. Half of those hospitalized were under the age of 12 and are not yet eligible to be vaccinated.

Related video: How adults should protect children from COVID-19 variants

“That makes the point that they need to be protected, first by decisions of their parents, and then secondly by school boards if they decide to take action in that regard,” Hutchinson said. The governor also urged the state Legislature to consider modifying or rescinding a law passed earlier this year that prohibits the state and public school districts from imposing mask mandates.

“There’s actually data out there that if adults get vaccinated, to a degree, that decreases COVID cases in children,” Dr. Thomas Russo, professor and chief of infectious disease at the University at Buffalo in New York, tells Yahoo Life. He cited a study published in June in the journal Nature Medicine that analyzed COVID-19 cases across all age groups in Israel as more people got vaccinated. (At the time, Israelis aged 16 and up were authorized to get the vaccine.) For every 20 percent increase in the number of 16- to 50-year-olds who were vaccinated, the amount of unvaccinated Israelis under the age of 16 who tested positive for COVID-19 fell by half.

“If you have more individuals vaccinated, you’re going to diminish cases, including decreasing the likelihood of having cases in your household,” Russo says.

“If you have a population that has a lot of unvaccinated people, COVID is going to be more prevalent — it just is at this point,” Dr. Danelle Fisher, a pediatrician and chair of pediatrics at Providence Saint John's Health Center in Santa Monica, Calif., tells Yahoo Life. And, she points out, the Delta variant is also likely to be more widespread, given that it’s currently responsible for more than 83.4 percent of new COVID-19 cases in the country, per data from the Centers for Disease Control and Prevention. “Delta is so much more infectious,” she says. “That’s why we’re seeing more COVID-19 now in kids where we haven’t before — and the adults around them are helping to spread it.”

But “the currently approved vaccines are effective against the Delta variant,” Dr. Anand Sekaran, medical director of inpatient services at Connecticut Children’s Medical Center, tells Yahoo Life. “Therefore, increased vaccination rates in a community correlate with decreased COVID-19 cases, in adults and children,” he continues. “Vaccination rates are extremely important in lowering these cases.”

Other than parents getting vaccinated, experts say there are a few additional things they can do to keep their children safe. “If anyone in your house is 12 and up, get them vaccinated,” Russo says. “They will provide indirect protection for younger family members.” Sekaran also recommends that parents encourage careful hand hygiene in kids, and have them wear masks “when appropriate.” That includes in indoor settings, large crowds and while traveling, he says.

Russo says that outdoor sports are “likely fine,” but urges parents to consider having their children wear masks when they do indoor playdates. “Anytime they interact with other unvaccinated individuals, they should wear masks, particularly in indoor settings,” he says.

Fisher says she’s been asked about travel “a lot” by families, and she urges parents to do their research about COVID-19 case counts in advance. “I feel a little more comfortable with people traveling to areas where vaccination rates are high and COVID-19 cases are low,” she says. “Traveling to Florida, which is a state that is seeing a ton of COVID ... I would proceed with a lot more caution than if someone were to be traveling to the Northeast, where there has not been a huge bump in cases.”

Overall, experts urge parents to stay vigilant in protecting their kids against COVID-19. “We can’t forget that these things have led us to have some initial success,” Sekaran says.