Although the daily averages of new COVID-19 cases are on the decline in Hawaii, health officials are warning the public that levels are still high enough to warrant indoor masking.

The state’s seven-day average of new cases fell to 832 on Wednesday, representing a continued downward trend for the third week in a row, according to the Hawaii Department of Health. The average reflects new cases per day during a time frame spanning June 11-17.

The state’s average positivity rate also dropped to 17.1% compared with 18.9% reported June 15, according to DOH, marking the second consecutive weekly decline. The positivity rate reflects test results from a different set of seven days — June 14-20.

DOH on Wednesday also reported 15 more deaths, bringing the total coronavirus death toll to 1,489.

Based on trends over the past few weeks, health experts believe cases in Hawaii have reached a plateau — at least for now.

On June 16 , the Hawaii Pandemic Applied Modeling Work Group said daily cases for Honolulu, Maui and Hawaii counties were leveling off. Kauai County also was plateauing, the work group said, with daily cases slightly trending down, but assuming that reinfection occurs six months after initial infection, a potential new surge may be on the horizon soon.

Because Kauai County experienced the greatest surge from omicron BA.1, it’s expected to be the first county to undergo a reinfection period, said HiPAM, but noted this was “purely an estimate.”

Hospitalizations, meanwhile, appeared to level off this week, with the state dashboard Wednesday reporting 196 patients with COVID-19 in Hawaii hospitals, down from 218 reported the previous Wednesday. Of the 196, 10 were in intensive care and three on ventilators.

The highest daily number of hospitalizations occurred June 16, with 225 COVID patients, according to the Healthcare Association of Hawaii. The seven-day rolling average for the week was at about 200.

HAH expects hospitalizations — a lagging indicator — to continue rising into July, but does not expect them to reach the same highs as during the delta surge.

The U.S. Centers for Disease Control and Prevention as of Wednesday still ranked Kauai, Honolulu, Maui and Hawaii counties as high-level communities for COVID-19 impacts.

Under CDC guidelines, people living in high-level communities should wear a well-fitting mask in public indoor settings and on public transportation, regardless of vaccination status. Those in medium-level communities should consider masking based on personal risk.

The community level rankings — based on case rates and hospital admission rates per 100,000, and percent of hospital beds occupied — are updated every Thursday.

Tim Brown, an epidemiologist at the East-West Center in Manoa, warned that transmission levels in the isles are still high, and the matter should not be downplayed.

“We are still in a very epidemic situation, yet we’re downplaying it,” said Brown during the Honolulu Star-­Advertiser “Spotlight Hawaii” live webcast that aired Monday. “We’re acting like nothing’s going on, but the reality is people should be masking.”

Brown estimated that Hawaii is probably a week or so out from the peak of the current surge, but said that the way down will be slow.

“Even if we are on the downslope it’s a slow downslope,” he said. “We’re still going to have high rates of community spread probably through mid-July at the rate we’re declining now.”

Additionally, the unknown impacts of omicron subvariants BA.4 and BA.5 have yet to be factored in, leaving open the question of whether the downward trend continues or not.

Omicron subvariants BA.4 and BA.5 are on the rise in Europe, he said, driving hospitalizations up in Portugal and Ireland.

Nationally, BA.4 and BA.5 are also on the rise, and now make up about 35% of new coronavirus cases in the U.S., while BA.2.12.1 makes up 56%, according to the latest data from CDC.

DOH’s variant report said BA.4 and BA.5 are estimated to be about 1.6 and 1.8 times more transmissible, respectively, than BA.2, and may have an increased ability to evade antibodies elicited by vaccination or prior infection.

BA.2.12.1 is now the dominant lineage in Hawaii, making up 57% of variants circulating in the state, but cases of BA.4 and BA.5 are rising.

There are now 24 confirmed cases — nine of BA.4 and 15 of BA.5 — in Hawaii via genome sequencing by DOH’s State Laboratories Division, according to the latest report— triple the number in the previous report.

While previously the two variants were detected in only Hawaii and Honolulu counties, they’re now present in all four major counties — with most in Honolulu, four in Hawaii County, two in Maui County and one in Kauai County.

Many epidemiologists are concerned about the ability of the latest omicron subvariants to evade immunity and spur reinfections.

Dr. Eric Topol, professor of molecular medicine at Scripps Research in San Diego, is troubled by a new study on COVID reinfections.

The study, not yet peer reviewed, analyzed more than 5.6 million people from the U.S. Department of Veterans Affairs database. Divided into cohorts with first infections, reinfections and a noninfected control group, the study showed risks increased with repeat infections.

“We show that compared to people with first infection, reinfection contributes additional risks of all-cause mortality, hospitalization, and adverse health outcomes in the pulmonary and several extrapulmonary organ systems,” the authors concluded in their abstract.

Therefore, “reducing overall burden of death and disease due to SARS-CoV-2 will require strategies for reinfection prevention.”

Topol said these findings are worrisome because reinfection was quite rare before the omicron wave hit, but reinfections have now become much more common.

“The Omicron BA.2, BA.2.12.1, BA.4, and BA.5 have progressively increased immune escape and there is limited cross-immunity with BA.1, the Omicron version that about half of Americans got infected with early in 2022,” wrote Topol in his newsletter, “Ground Truths.”

Brown emphasized the importance of continuing to mask up, and of getting more eligible Hawaii residents boosted. This up-and-down cycle could potentially go on for years, he said, if transmission continues.

“Right now, this let-it-rip attitude is, in fact, contributing to the more rapid evolution of the virus,” he said, “and therefore, contributing to it getting around our existing protections.”

The DOH, meanwhile, greenlighted vaccines for Hawaii’s keiki ages 6 months to 4 years old upon clearance from federal authorities Saturday. Hawaii Pacific Health, pediatrician’s offices and others are now taking appointments.

As of Wednesday, 77.9% of Hawaii’s population had completed primary COVID-19 vaccines, with 41.2% boosted once and 8.6% boosted twice.

DOH estimates there are about 80,000 children under age 5 now eligible for the vaccines.

Sites offering COVID-19 vaccines and boosters are listed online at hawaiicovid19.com/vaccine.