Covid-19 reinfections now account for about 10% of the confirmed cases in Hawaii, health officials said Wednesday, as the state began including the backlogged repeat cases in its official count.

The Department of Health reported 10,995 reinfections dating back to September 2020, raising its weekly count to 12,755. But the seven-day positivity rate was 5.7%, reflecting an overall decline in the spread of the coronavirus.

The announcement came amid a push for Hawaii residents to get the bivalent booster shot, which targets the original coronavirus strain as well as the highly contagious omicron subvariants BA.4 and BA.5. While people may get Covid-19 multiple times, experts say vaccinations provide increased protection against severe illness.

“It’s important to know that reinfection is happening,” State Epidemiologist Sarah Kemble said at a news conference. “It certainly informs choices about getting vaccinated. We’re looking at both these counts now, and the science that’s coming out that says even when you’ve previously been infected, getting a vaccine or booster is also going to provide additional protection to you, even for those that already had the infection.”

More than 77% of the state’s population is fully vaccinated, 45.3% received the first booster shot and 13% received a second.

Reinfections used to be extremely rare but have become more common as the virus evolves, Kemble said.

“Recently, as we’ve seen shifts in variants, and now with BA.5, we’re up to about 10% of our cases recently reported being reinfections,” Kemble said. “So we’re seeing a much more prominent trend with reinfections now.”

The state dashboard used to only count people once regardless of how many times they got Covid-19. Now each case will be recorded separately, Kemble said, cautioning that will lead to higher numbers. She noted the official figures don’t include home tests that often aren’t reported to the health department.

“We’re not going to be able to capture those reinfections, so I would say, in actuality, the true number of reinfections is probably higher than what we are able to show in these numbers,” she said.

Of the 1,145 new cases reported Wednesday, 117 were reinfections, according to DOH spokesman Brooks Baehr.

Hawaii has reported a total of 355,959 cases since the pandemic began in the islands in March 2020. The state also reported seven new deaths over the past week, raising the total to 1,686.

Kemble said it’s unclear if people who get Covid more than once become sicker than those who are only infected once.

“In general, reinfection tends to be more mild for most combinations, but that’s not always the case,” Kemble said. “Unfortunately, some people who are reinfected still do end up in the hospital or can die. I think this is really important to know — that vaccines are a way to protect yourself from those more severe outcomes.”

No data is available on how many people reinfected with Covid-19 were vaccinated or unvaccinated, according to Kemble. She also said there’s no complete understanding of whether some people are more vulnerable to reinfection.

Civil Beat’s health coverage is supported by the Atherton Family Foundation, Swayne Family Fund of Hawaii Community Foundation, Cooke Foundation and Papa Ola Lokahi.