Penny Brown, 2, is held by her mother, Heather Brown, as her nose is lightly swabbed during a test for COVID-19 at a walk-up testing site at Chief Sealth High School, Friday, Aug. 28, 2020, in Seattle. Credit: Elaine Thompson / AP

COVID-19 cases in younger children drove Maine to record infection levels in November, highlighting the continued threat posed by the delta variant for a group generally considered less affected by the virus.

Maine reported more new cases of the virus in November than any other month, with unvaccinated people continuing to account for a majority of cases despite making up a minority of the state’s population at this point. The high infection rate has also contributed to record hospitalization numbers, with 367 COVID-19 patients hospitalized as of Tuesday.

While cases have been up across all age groups, most of last month’s rise was driven by cases among young children who are either unable or less likely to be vaccinated against COVID-19, according to data from the Maine Center for Disease Control and Prevention.

The number of Maine adults aged 20 and older just barely set a record last month, with 11,465 cases recorded through Nov. 29 compared to 11,383 in January of this year. But the 3,685 cases recorded among children younger than 12 during that time period was a 69 percent jump compared to the previous record set after schools resumed session in September.

Among children younger than 5, who remain ineligible for any COVID-19 vaccines, about 1 out of every 71 tested positive in November alone, state data show. There were five new hospitalizations among children in that age group.

Even with that increase among the youngest children, hospitalization rates in kids remain far lower than in adults. But higher infection rates have disturbed schooling in many parts of the state. Nearly 200 Maine schools were seeing COVID-19 outbreaks as of last week. Outbreaks have been more likely in areas with higher community transmission of the virus, and some schools have temporarily gone remote due to the rise in cases.

The American Academy of Pediatrics also found Maine was among the states to see the greatest percentage in cases among children in the latter half of November. The cumulative COVID-19 case rate among children here remains similar to the national average.

Increased vaccination rates among children could tamper down cases among children, as they have among vaccinated adults. But a month after federal regulators authorized the lower dosage Pfizer vaccine for use in children between the ages of 5 and 11, only about 31 percent of kids in that age group have received at least one dose, compared with about 82 percent of Mainers aged 12 and older.