VANCOUVER, Wash. (KOIN) — More than 100 cases of fully vaccinated Washingtonians getting the coronavirus — called breakthrough cases, since the virus breaks through the vaccine — are being investigated.

But the Washington State Department of Health reminds people that’s about .01% of vaccinated people in Washington. The breakthrough cases have been reported in 18 counties.

Of the reported cases, 2 are in Cowlitz County and 15 in Clark County. In Clark County about 60,000 residents are fully vaccinated — about 10% of the county population.

“Among the 15 cases in Clark County 8 have had symptoms, 3 hospitalized. no deaths,” said Clark County Public Health Officer Dr. Alan Melnick.

One of the concerns is the new coronavirus variants identified in Cowlitz County. Test samples were were to check, but health officials also look into whether there is an issue with storage, transportation or lot number of the vaccine.

So far, they have not found a link to a brand of vaccine. The people affected by the breakthrough cases ranged in age from their 20s to their 80s.

“Precisely because we are still at this stage where we are concerned about resurgence and variants and vaccine not 100% effective, we still urge people to be careful in public,” Melnick said.

Health officials said there are likely more breakthrough cases that haven’t been identified, since people might not have symptoms or haven’t been tested.

“If you’ve been in close contact with a case, you are fully vaccinated and develop symptoms, we sure would want you to get tested precisely for what I mentioned early,” Melnick said. “We are concerned those folks might have a variant and we want to identify any variants in our community.”

That’s why the COVID protocols remain in place: wear a mask in public, maintain social distancing and wash your hands.