How COVID-19 shots for children help prevent dangerous new variants

Solome Walker, 9, looks down at her bandage after getting her first Pfizer COVID-19 shot at a vaccination clinic for young students at Ramsey Middle School on Saturday, Nov. 13, 2021 in Louisville, Ky. Scientists say vaccinating kids against COVID-19 should not only slow the spread of the coronavirus but also help prevent potentially-dangerous variants from emerging. Each new infection brings another opportunity for the virus to mutate and evolve dangerous new traits. (AP Photo/Laura Ungar)
Solome Walker, 9, looks down at her bandage after getting her first Pfizer COVID-19 shot at a vaccination clinic for young students at Ramsey Middle School on Saturday, Nov. 13, 2021 in Louisville, Ky. Scientists say vaccinating kids against COVID-19 should not only slow the spread of the coronavirus but also help prevent potentially-dangerous variants from emerging. Each new infection brings another opportunity for the virus to mutate and evolve dangerous new traits. (AP Photo/Laura Ungar)

LOUISVILLE, Ky. (AP) - Cadell Walker rushed to get her 9-year-old daughter Solome vaccinated against COVID-19 - not just to protect her but to help stop the coronavirus from spreading and spawning even more dangerous variants.

"Love thy neighbor is something that we really do believe, and we want to be good community members and want to model that thinking for our daughter," said the 40-year-old Louisville mom, who recently took Solome to a local middle school for her shot. "The only way to really beat COVID is for all of us collectively to work together for the greater good."

Scientists agree. Each infection - whether in an adult in Yemen or a kid in Kentucky - gives the virus another opportunity to mutate. Protecting a new, large chunk of the population anywhere in the world limits those opportunities.

That effort got a lift with 28 million U.S. children 5-11 years old now eligible for child-sized doses of the Pfizer-BioNTech vaccine. Moves elsewhere, like Austria's recent decision to require all adults to be vaccinated and even the U.S. authorizing booster shots for all adults on Friday, help by further reducing the chances of new infection.

Vaccinating children also means reducing silent spread, since most have no or mild symptoms when they contract the virus. When the virus spreads unseen, scientists say, it also goes unabated. And as more people contract it, the odds of new variants rise.

David O'Connor, a virology expert at the University of Wisconsin-Madison, likens infections to "lottery tickets that we're giving the virus." The jackpot? A variant even more dangerous than the contagious delta currently circulating.

"The fewer people who are infected, the less lottery tickets it has and the better off we're all going to be in terms of generating the variants," he said, adding that variants are even more likely to emerge in people with weakened immune systems who harbor the virus for a long time.

Researchers disagree on how much children have influenced the course of the pandemic. Early research suggested they didn't contribute much to viral spread. But some experts say children played a significant role this year spreading contagious variants such as alpha and delta.

Getting children vaccinated could make a real difference going forward, according to estimates by the COVID-19 Scenario Modeling Hub, a collection of university and medical research organizations that consolidates models of how the pandemic may unfold. The hub's latest estimates show that for this November through March 12, 2022, vaccinating 5- to 11-year-olds would avert about 430,000 COVID cases in the overall U.S. population if no new variant arose. If a variant 50 percent more transmissible than delta showed up in late fall, 860,000 cases would be averted, "a big impact," said project co-leader Katriona Shea, of Pennsylvania State University.

Delta remains dominant for now, accounting for more than 99 percent of analyzed coronavirus specimens in the United States.