YORBA LINDA, Calif. (KABC) -- Orange County Health Care Agency officials said Wednesday they are still investigating what could have caused a COVID-19 outbreak at a Yorba Linda school that forced the entire sixth-grade class to quarantine.
Travis Ranch School sixth-graders were sent home and learning via Zoom this week after a breakout of "dozens of cases," according to the Placentia-Yorba Linda Unified School District.
Dr. Regina Chinsio-Kwong, the deputy county health officer, said the outbreak was similar to others nationally.
"Most of the people were not vaccinated or partially vaccinated," Chinsio-Kwong told reporters. "It would have helped if more people at the school were vaccinated.'"
"What we do know is there was potentially one adult who was not vaccinated and symptomatic" on campus, Chinsio-Kwong added. "And many of the kids in the classroom were not vaccinated."
To play it safe, the district decided to opt for virtual education for the week, she said.
"Maybe it is helpful that we're going into the winter break," she said.
The vast majority of Orange County schools show confirmed COVID cases in the single digits.
Travis Ranch, however, shows 54 student cases as of Wednesday - that's three times more than the next highest school.
Orange County health officials said about 200,000 children in the county between the ages of 5 and 11 have not received their first dose of the vaccine. For those between the ages of 12 and 17, the number is 70,000.
"That's still a significant portion of kids who need to get vaccinated," Chinsio-Kwong said.
Dr. David Bronstein, a pediatric infectious disease specialist with Kaiser Permanente, supports the school's decision to quarantine, saying it's important to squelch outbreaks quickly.
"We do see kids being able to get it and spread it even at higher rates than adults right now because it is such a vulnerable population," Bronstein said.
With the holidays coming up and plenty of days off, experts say it's the perfect time for parents to get their kids vaccinated and help avoid even bigger problems that are looming in the days ahead.
"Unfortunately, what we see every year, not just with COVID, as soon as kids do go back to school in January, they start swapping all the germs that they accumulated over winter break and you have these new outbreaks that happen," Bronstein said.
Meanwhile, Orange County has yet to report a case of the omicron variant, but Chinsio-Kwong said it's just a matter of time.
City News Service contributed to this report.