Orange County virus rates tick upward, with most new cases among those under 35

Visitors stroll through the food area at the Pier Plaza Fourth of July Festival in Huntington Beach on Friday.
(Kevin Chang / Staff Photographer)

Coronavirus infections and COVID-19 hospitalizations in Orange County are creeping up to levels not seen in months as the more transmissible Delta variant proliferates, provoking new concerns among health experts for those still unvaccinated.

“I’m worried about the trend,” Andrew Noymer, an epidemiologist and UC Irvine associate professor of population health and disease prevention, told City News Service earlier this week.

The Orange County Health Care Agency on Tuesday reported 1,050 new infections and nine deaths in the past seven days, bringing county totals to 257,826 cases and 5,133 fatalities.

Health officials recently transitioned from providing daily virus statistics to giving weekly updates each Tuesday, but figures provided on an online COVID-19 dashboard show 210 new infections were recorded on Thursday alone — the highest single-day total recorded since March 1.

Some 119 residents were being treated in Orange County hospitals for COVID-19 as of Tuesday, a 30% jump in the three-day average over last week, with 25 in intensive care units.

Health officials estimated about 90% of all new infections and 95% of hospitalizations are among unvaccinated individuals. And though about 56% of the population has been fully vaccinated, the unprotected remainder could threaten to overwhelm the county’s hospital system if the Delta variant continues its upward trajectory, Noymer said.

“It’s not a prediction…(but) 40% [of unvaccinated residents] is enough with these new variants, which are more transmissible, to generate enough cases to overrun the hospital system,” he continued.

The rate of new cases in Orange County remains much lower than the record-high infections logged in January, but a continuing upward trend has been observed in recent weeks.

OCHA figures from July 6 indicated an infection rate of 1.5 in 100,000, compared to 2.6 this week, while the county’s testing positivity rate doubled, from 0.9% two weeks earlier to 1.8% Tuesday.

A majority of new infections tracked this week occurred among residents under age 35, who accounted for more than 57% of cases. Those aged 25 to 34 accounted for 286 new infections, while residents 65 and older, who have significantly higher vaccination rates and represent a larger portion of the overall population, accounted for just 65 new infections.

Noymer said although people who have been vaccinated account for a few asymptomatic cases, the vaccine still offers significant protection from the COVID-19 disease and the Delta strain of the virus.

“Breakthrough infections remain rare and significantly milder clinically, including sometimes being asymptomatic,” he added. “And breakthrough infections really shouldn’t be a major talking point at this point — it’s not an epidemiologically significant factor. The current variants do not evade the vaccines.”

The UC Irvine professor encouraged OCHA to include information on its online dashboard showing how many new coronavirus cases occur among unvaccinated residents, to help combat misconceptions about the risks and benefits of the COVID-19 vaccine.

“[There’s] this yawning divide between the vaccinated and unvaccinated in new cases,” he said.

City News Service contributed to this report.

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