Utah parents are being advised not to overreact to a new study from New York showing that it took just over a month for the COVID-19 vaccine to offer children 5-11 years old virtually no protection from getting the virus while becoming less than 50% effective at keeping them out of the hospital.

“This is one study. Science is very much something where it’s important to look at many pieces of information before we draw conclusions that directly impact what we’re going to do,” state epidemiologist Dr. Leisha Nolen said Tuesday, adding she wants to see what’s happening in other places before accepting the results.

“Don’t take this as absolute fact,” she said. “Take this as good information that we really need to look into further.”

Nolen said the Utah Department of Health continues to recommend parents get their children vaccinated against COVID-19, even as the state moves toward treating the virus more like the flu or other endemic disease that remains deadly but is not as widespread.

“It’s always good to be prepared,” she said, for another wave of COVID-19 that’s “pretty certain” to hit at some point.

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And even if the data from New York suggests the vaccines may not stop young children from getting the virus, Nolen said “happily, they still have a reasonable protection against hospitalization. We know that’s what we’re really aiming for, right? We want to keep kids out of the hospital.”

The study, posted Monday by doctors and researchers at the New York State Department of Health and the University at Albany School of Public Health in New York, found that in fully vaccinated children ages 5-11, the vaccine’s protection against COVID-19 infections fell from 68% in mid-December to just 12% by the end of January.

When it came to preventing hospitalization during the surge of the incredibly transmissible omicron variant of the virus over the same time period, the two reduced doses of the Pfizer vaccine approved for that age group dropped in effectiveness from 100% to 48%.

For fully vaccinated adolescents and teens ages 12-17, the study found the declines in vaccine effectiveness during those weeks weren’t as steep, with protection against infection dropping from 66% to 51% and protection against severe illness falling from 85% to 73%.

A big difference in the vaccine’s effectiveness against infection between ages 11 and 12 — the study found in the week ending Jan. 30 that it was down to 11% for 11 year olds versus 67% for 12 year olds — suggest the size of the dose may be a problem. Children 5-11 receive 1/3 the dose given those 12 and older.

The new data follows disappointing results from clinical trials of an even smaller dose of the Pfizer vaccine in children under 5 years old. Last month, the Food and Drug Administration postponed a decision on whether to approve the shots for children as young as 6 months old until a study on the need for a third dose is completed.

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Nolen said it’s always a challenge to determine the proper dosage for children, and both the new study and the clinical trials support looking at whether the amount of vaccine needs to be adjusted for younger children and booster shots offered. Currently, booster shots are available only to those 12 and older.

Her issues with the New York study include what she said is a greater likelihood that children who are vaccinated against the virus would be tested if they show symptoms, possibly skewing the results, as well as the results of home testing not being included since they’re not reported to the government.

COVID-19 vaccinations have slowed in Utah since the peak of the omicron surge here, when cases rose about 13,000 a day and testing sites were so overwhelmed that Gov. Spencer Cox urged most Utahns with symptoms to skip the swab and simply stay home until they felt better.

Currently, 61% of all Utahns are fully vaccinated, meaning it’s been two weeks or more since their initial series of shots — two doses of the Pfizer or Moderna vaccines, or a single dose of Johnson & Johnson. But only 27% of Utah children aged 5-11 have gotten both doses of Pfizer, the only choice in the United States for those under 17.

Nolen said there’s always a concern that questions raised about the effectiveness of vaccines in children could keep parents from scheduling their shots.

“We do want to make sure people see there is still a benefit,” she said, describing the latest study as an example of being transparent about vaccines. “We’re not hiding data. We’re not trying to bias people’s understanding. It’s out there.”