It’s like deja vu, with a post-holiday surge happening all over again.

For the seventh day in a row Wednesday, Hawaii’s new daily coronavirus case numbers hit triple digits, repeating last year’s post-Fourth of July surge.

Health officials say the spike is due to the highly transmissible delta variant taking hold across the islands, a cause for concern as the state pushes to get 70% of the population vaccinated against COVID-19. The seven-day average daily case count of 113, as well as the positivity rate of 3.5%, is also significantly higher than it was at the same time last year.

The difference this summer, however, is that COVID-19 vaccines are available.

“It’s not as deadly as what we were experiencing a year ago,” said Hilton Raethel, head of the Healthcare Association of Hawaii. “We’re much better at treating COVID, and most older people are protected. But we could quite easily hit 100 patients in the hospital at the rate we’re going and that’s not a good thing.”

Raethel said some hospitals are already beginning to feel the strain, with no indication the rate of transmission will slow any time soon.

On Wednesday, the state Department of Health reported one new coronavirus-related death and 163 new confirmed and probable infections statewide, bringing the state’s totals since the start of the pandemic to 524 fatalities and 39,649 cases.

The latest fatality involved an Oahu man in his 50s with underlying health conditions who died at home.

The department also said it had detected an additional 69 delta variant cases, up from 57 from the last report July 12, bringing Hawaii’s total to 126 cases.

Vaccination rates are high for Hawaii’s kupuna but drop for those in younger age groups. Only a little more than half of adults ages 18 to 29 have completed vaccinations, according to DOH.

Health officials said about 97% of those newly infected with COVID-19 in Hawaii are the remaining third of the state’s population who remain unvaccinated.

“It actually is quite alarming because the infection rate in the unvaccinated population is actually higher now than what it was in the entire population last year,” Raethel said.

Hospitalization rates are also on the rise, officials said, and among the COVID-19 patients landing in the hospital are unvaccinated patients in their 20s and 30s.

Lt. Gov. Josh Green said there were 72 patients with COVID-19 in hospitals on Wednesday, including more than a dozen in intensive care units. Among those in ICUs were a 23-year-old and 32-year-old, both of whom were unvaccinated.

Young people have a better chance of pulling through an infection, he said, and while daily coronavirus cases are expected to continue rising, the fatality rate is expected to drop.

So there are some parallels to the last surge in that there is community spread, he said, but this time around two-thirds of the population is either partially or fully immunized.

“It’s deja vu for a smaller population,” he said. “It’s deja vu for only a third of the state and not the whole state.”

Daily coronavirus case counts are expected to continue rising with the delta variant in the islands for weeks to come, according to Green, “because the delta variant is very contagious and too many people remain unvaccinated.”

According to a forecast by University of Hawaii mathematics professor Monique Chyba and her research team, in partnership with the Hawaii Pandemic Applied Modeling Work Group, COVID-19 cases in the state are expected to continue growing well into the fall.

Based on Chyba’s worst-case scenario forecast model, infections are expected to continue rising — well above 100 new cases per day — through September and peak some time in October before flattening out, assuming that 70% of Hawaii’s population is vaccinated.

If only 65% of Hawaii’s population is vaccinated, numbers should trend higher.

A more conservative forecast at the 65% vaccination rate has the numbers rising less steeply but hovering around 100 new cases per day through the rest of the year.

“What is clear from the data is the delta variant is dominating very quickly, even here in Hawaii,” Chyba said. “It’s the only variant increasing, so that’s the one we have to really be concerned with.”

Reopening or lifting mitigation measures such as the indoor mask mandate must be done cautiously, she warned, and should not be done prematurely. Also, more younger people need to get vaccinated against COVID-19.

Chyba said there are still many unknowns and variables but she and her research team will be watching hospitalization rates very closely in the next few weeks.

“People need to take responsibility,” she said. “We do not want to go back to Tier 3 or Tier 2 (of the city’s coronavirus restrictions). For the people who have the opportunity to get vaccinated there is no doubt the vaccine is preventing you from going to the hospital, even with the delta variant.”

This leaves children under 12, who are not yet eligible for vaccines, and the unvaccinated even more susceptible than ever, officials said.

As of Wednesday, DOH reported that 1,733,089 doses of COVID-19 vaccines had been administered in Hawaii as of Tuesday. So far, 59.4% of the state’s population is completely vaccinated, while 66% have received at least one dose.

While the state has done well, current rates of vaccination have waned considerably.

At the peak of vaccination demand in April, the state was administering about 80,000 doses per week. This past week, Raethel said, the state administered only about 15,000 doses. At the current pace, it could be several months before the state hits its 70% vaccination goal.

“There’s only basically two choices here,” he said. “Either we lock down the economy again or figure out how to get more people vaccinated to slow down the spread.”

The COVID-19 vaccines are incredibly safe and effective, Raethel said, but time is running short.

“While people are getting vaccinated, this delta variant is continuing to spread and potentially continuing to mutate further.”