EDITOR’S NOTE: Multimedia journalist Nathalie Basha reported on the new requirement to show proof of COVID-19 vaccination at indoor businesses in Los Angeles, including coffee shops, gyms and hair salons. Click the arrow above to watch the video.

LOS ANGELES (CNS) — With cooler fall and winter weather on the horizon, Los Angeles County has already begun to see a slight uptick in COVID-19 transmission, while other pandemic-tracking metrics have plateaued, prompting a call Thursday from the public health director for renewed commitment to infection-control measures.

Barbara Ferrer reiterated in an online briefing Thursday that the county's seven-day cumulative virus-transmission rate as estimated by the U.S. Centers for Disease Control and Prevention was 84 new cases per 100,000 residents this week, up from the mid-70s last week, keeping the county entrenched in the "substantial" transmission category.

"Cooler weather has arrived, and with it, conditions that favor COVID transmission as we gather inside to stay warm and for celebrations and gatherings," Ferrer said. "While vaccination remains our most powerful tool for preventing spread of the virus, when we have this much transmission, masking up indoors and in crowded outdoor spaces is still an important layer of protection for everyone. We ask that you continue to do your part and adhere to the masking requirements, which are likely to remain in place for the remainder of this calendar year as we all work hard to reduce community transmission rates to the 'moderate' tier." 

Reaching the CDC's "moderate" transmission tier requires the county to fall below a seven-day new case rate average of 50 per 100,000 residents. To reach that level, the county would have to report a daily new case number of about 700. The county on Thursday reported 1,829 new cases, although nearly 400 of them actually dated back to late October due to a reporting lag from a large testing lab, and other cases may have also occurred earlier but are just now being confirmed. 

Ferrer also noted that the average number of people hospitalized in the county has plateaued at about 630 people per day, and the number of daily deaths is averaging about seven to eight.

"We're seeing a plateau across all of our metrics, with signs of a possible uptick in transmission over the more recent days," she said.

She again laid primarily blame for increasing transmission at the feet of unvaccinated residents, who she said are seven times more likely to become infected and 27 times more likely to be hospitalized. Rising transmission will also naturally lead to more "breakthrough" infections among the vaccinated population, and when those cases occur among older and more medically fragile people, "some may even pass away."

"This is because unvaccinated people create risk for everyone," she said. "Vaccination cannot entirely immunize us against the consequences of the chances unvaccinated people take. Their risk eventually spills over into that of vaccinated residents, and it is leading all of us to continuing to take additional protections like masking to reduce the chances of getting and passing on the virus."

Ferrer reported an additional 12 COVID-19 deaths on Thursday, giving the county an overall virus death toll of 26,695. The 1,829 new cases reported Thursday increased the cumulative pandemic total to 1,498,393. 

The average daily rate of people testing positive for the virus was 1.6% as of Thursday, up from 1.2% a week ago.

According to state figures, there were 650 COVID-positive patients hospitalized in the county as of Thursday, down from 662 on Wednesday. Of those hospitalized, 155 were being treated in intensive care, up slightly from 152 on Wednesday.

The county's vaccination rate remained largely unchanged from last week, with 80% of eligible residents aged 12 and over receiving at least one dose, and 72% fully vaccinated. Among all 10.3 million residents, including those not eligible for shots, 69% have received one dose, and 62% are fully vaccinated.

Children aged 5-11 became eligible for shots this week, a group that includes about 900,000 kids in Los Angeles County.