By MARTHA BEL­LISLE | AS­SO­CI­AT­ED PRESS

SEAT­TLE (AP) — The omi­cron-fu­elled surge that is send­ing COVID-19 cas­es rock­et­ing in the U.S. is putting chil­dren in the hos­pi­tal in close to record num­bers, and ex­perts lament that most of the young­sters are not vac­ci­nat­ed.

“It’s just so heart-break­ing,” said Dr. Paul Of­fit, an in­fec­tious-dis­ease ex­pert at Chil­dren’s Hos­pi­tal of Philadel­phia. “It was hard enough last year, but now you know that you have a way to pre­vent all this.”

Dur­ing the week of Dec. 21-27, an av­er­age of 334 chil­dren 17 and un­der were ad­mit­ted per day to hos­pi­tals with the coro­n­avirus, a 58% in­crease from the week be­fore, ac­cord­ing to the Cen­ters for Dis­ease Con­trol and Pre­ven­tion.

The pre­vi­ous peak over the course of the pan­dem­ic was in ear­ly Sep­tem­ber, when child hos­pi­tal­iza­tions av­er­aged 342 per day, the CDC said.

On a more hope­ful note, chil­dren con­tin­ue to rep­re­sent a small per­cent­age of those be­ing hos­pi­tal­ized with COVID-19: An av­er­age of over 9,400 peo­ple of all ages were ad­mit­ted per day dur­ing the same week in De­cem­ber. And many doc­tors say the young­sters com­ing in now seem less sick than those seen dur­ing the delta surge over the sum­mer.

Two months af­ter vac­ci­na­tions were ap­proved for 5- to 11-year-olds, about 14% are ful­ly pro­tect­ed, CDC da­ta shows. The rate is high­er for 12- to 17-year-olds, at about 53%.

FILE - Retired registered nurse Jill Rill, right, puts a bandage on Jackson Stukus, 11, after he received a Pfizer COVID-19 vaccine as his mom Kristin looks on during the first COVID-19 vaccine clinic in Franklin County for children age 5-11 at Nationwide Children's Hospital in Columbus, Ohio, Nov. 3, 2021. The omicron-fueled surge that is sending COVID-19 cases rocketing in the U.S. is putting children in the hospital in close to record numbers, and experts lament that most of the youngsters are not vaccinated. (AP Photo/Paul Vernon, File)

The is­sue is tim­ing in many cas­es, said Dr. Al­bert Ko, pro­fes­sor of epi­demi­ol­o­gy and in­fec­tious dis­eases at the Yale School of Pub­lic Health. Younger chil­dren were not ap­proved for the vac­cine un­til No­vem­ber, and many are on­ly now com­ing up on their sec­ond dose, he said.

Of­fit said none of the vac­cine-el­i­gi­ble chil­dren re­ceiv­ing care at his hos­pi­tal about a week ago had been vac­ci­nat­ed, even though two-thirds had un­der­ly­ing con­di­tions that put them at risk — ei­ther chron­ic lung dis­ease or, more com­mon­ly, obe­si­ty. On­ly one was un­der the vac­ci­na­tion age of 5.

The scenes are heart-wrench­ing.

“They’re strug­gling to breathe, cough­ing, cough­ing, cough­ing,” Of­fit said. “A hand­ful were sent to the ICU to be se­dat­ed. We put the at­tach­ment down their throat that’s at­tached to a ven­ti­la­tor, and the par­ents are cry­ing.”

None of the par­ents or sib­lings was vac­ci­nat­ed ei­ther, he said.

The next four to six weeks are go­ing to be rough, he said: “This is a virus that thrives in the win­ter.”

Over­all, new cas­es in Amer­i­cans of all ages have sky­rock­et­ed to the high­est lev­els on record: an av­er­age of 300,000 per day, or 2 1/2 times the fig­ure just two weeks ago. The high­ly con­ta­gious omi­cron ac­count­ed for 59% of new cas­es last week, ac­cord­ing to the CDC.

Still, there are ear­ly in­di­ca­tions that the vari­ant caus­es milder ill­ness than pre­vi­ous ver­sions, and that the com­bi­na­tion of the vac­cine and the boost­er seems to pro­tect peo­ple from its worst ef­fects.

Parker McKenzie, 10, right, receives a Pfizer COVID-19 vaccine from nurse practitioner Amy Wahl with distraction help from certified child life specialist Haylee Rogers during the first COVID-19 vaccine clinic in Franklin County for children age 5-11 at Nationwide Children's Hospital in Columbus, Ohio Wednesday, Nov. 3, 2021. The omicron-fueled surge that is sending COVID-19 cases rocketing in the U.S. is putting children in the hospital in close to record numbers, and experts lament that most of the youngsters are not vaccinated. (AP Photo/Paul Vernon)

In Cal­i­for­nia, 80 COVID-19-in­fect­ed chil­dren were ad­mit­ted to the hos­pi­tal dur­ing the week of Dec. 20-26, com­pared with 50 in the last week of No­vem­ber, health of­fi­cials said.

Seat­tle Chil­dren’s al­so re­port­ed a bump in the num­ber of chil­dren ad­mit­ted over the past week. And while they are less se­ri­ous­ly ill than those hos­pi­tal­ized over the sum­mer, Dr. John McGuire cau­tioned that it is ear­ly in the omi­cron wave, and the full ef­fect will be­come ap­par­ent over the next sev­er­al weeks.

New York health au­thor­i­ties have al­so sound­ed the alarm.

The num­ber of chil­dren ad­mit­ted to the hos­pi­tal per week in New York City with COVID-19 went from 22 to 109 be­tween Dec. 5 and Dec. 24. Across all of New York state, it went from 70 to 184. Over­all, al­most 5,000 peo­ple in New York were in the hos­pi­tal with COVID-19.

“A four­fold in­crease makes every­body jump with con­cern, but it’s a small per­cent­age,” Ko said of the New York City fig­ures. “Chil­dren have a low risk of be­ing hos­pi­tal­ized, but those who do are un­vac­ci­nat­ed.”

FILE - Graham Roark, 8, receives the Pfizer COVID-19 vaccine for children 5 to 11 years from Lurie Children's hospital registered nurse Virginia Scheffler at the hospital Nov. 5, 2021, in Chicago. The omicron-fueled surge that is sending COVID-19 cases rocketing in the U.S. is putting children in the hospital in close to record numbers, and experts lament that most of the youngsters are not vaccinated. (AP Photo/Nam Y. Huh, File)

Dr. Al Sac­chet­ti, chief of emer­gency ser­vices at Our La­dy of Lour­des Med­ical Cen­ter in Cam­den, New Jer­sey, like­wise said vac­ci­nat­ed chil­dren are han­dling the omi­cron out­break ex­treme­ly well.

“It makes a big dif­fer­ence in how these kids tol­er­ate the dis­ease, par­tic­u­lar­ly if the child’s got some med­ical is­sues,” he said.

COVID-19 deaths have proved rare among chil­dren over the course of the pan­dem­ic. As of last week, 721 in the U.S. had died of the dis­ease, ac­cord­ing to da­ta re­port­ed to the Amer­i­can Acad­e­my of Pe­di­atrics. The over­all U.S. death toll is more than 800,000.

Al­most 199,000 child COVID-19 cas­es were re­port­ed in the week of Dec. 16-23, the pe­di­atrics group said. That was about 20% of the more than 950,000 to­tal cas­es re­port­ed that week.

While many of these chil­dren will re­cov­er at home, they may have con­tact with oth­ers who are at much greater risk, said Dr. Ja­son Terk, a pe­di­a­tri­cian in North Texas. He cared for a 10-year-old boy with COVID-19 who man­aged the dis­ease well, but his fa­ther got sick and died, he said.

“The death of a par­ent is dev­as­tat­ing, but the tox­ic stress for a young per­son in this sit­u­a­tion is dif­fi­cult to mea­sure,” he said.