(CNN) Covid-19 cases among children are on the rise yet again, according to a report from the American Academy of Pediatrics published Monday.
New cases reported among children last week were up nearly 24% over the previous week, the report said. For the week ending December 9, there were at least 164,289 new cases among children -- that's more than 31,000 new cases than the week before.
Case numbers are still considered "extremely high," with kids accounting for a disproportionate number of new cases. Children make up about a quarter of all new cases, but only 22.2% of the US population, the report said.
Since the start of September, there have been nearly 2.1 million new Covid-19 cases in children, the report said. This marks the 18th week in a row that more than 100,000 children have been diagnosed with Covid-19.
Children between 5 and 11 have been eligible to get a Covid-19 vaccine shot since early November when Dr. Rochelle Walensky, the US Centers for Disease Control and Prevention director, endorsed a recommendation to vaccinate the age group.
As far as children getting a booster shot, the US Food and Drug Administration authorized the Pfizer vaccine for use as a booster in people ages 16 and 17. Just like adults, 16 and 17-year-olds are eligible for a booster six months after they've had their second dose.
It's still less likely for children to be hospitalized with Covid-19 than adults, but in the states that report hospitalizations by age, kids made up between 1.7% and 4% of those who needed to be treated at the hospital for Covid-19, a number that has been consistent throughout the pandemic, the AAP report said.
Deaths also account for a small percentage of total cases. Six states reported zero child deaths from Covid-19.
In states reporting death by age, 0% to 0.03% of all child Covid-19 cases resulted in death, according to the academy. But 992 children have died from Covid-19 in the US since the start of the pandemic, an increase of 18 since last Monday, according to the CDC.
The CDC recommends all adults get a Covid-19 vaccine booster. Adults who have had the Pfizer or Moderna Covid-19 vaccines are eligible to get a booster six months after their second shot. Those who got the Johnson & Johnson one-shot vaccine are eligible for a booster of any authorized vaccine two months after their first dose.
As far as younger children, it's unclear when, or even if, they will need a booster. Pfizer told CNN Monday that it is still looking at the data. The company said it has not yet begun a study on boosters in this younger demographic. Moderna and Johnson & Johnson still don't have a Covid-19 vaccine for kids under 18.