Health officials in Clallam and Jefferson counties say more than 650 residents were administered the one-shot Johnson & Johnson COVID-19 vaccine before the CDC paused its use over concerns about a rare but serious bloodclotting disorder possibly connected with the vaccine.

In Clallam County, where cases spiked to 101 on Saturday for the first half of April alone, Health Officer Allison Berry said those among the 449 residents who received the vaccine have little to worry about.

There have been six cases of severe clotting issues in young women among about 6 million people nationwide who received the Johnson & Johnson vaccine, she said.

“It’s a very, very rare outcome, but it is a very serious one,” Berry said Friday in her weekly coronavirus briefing.

“The problem from having a severe outcome from (the) Johnson & Johnson (vaccine) is less than your likelihood of winning the lottery.”

There are no clotting issues with the two-dose Moderna and Pfizer vaccines. A clinic scheduled today at Port Angeles High School where the Johnson & Johnson vaccine was to be administered was switched over to Moderna, for which county residents 18 and older are eligible.

Berry reported 13 new COVID-19 cases Friday compared to Thursday and three more Saturday, she said in subsequent text message Saturday. That gives Clallam County 1,166 cases, 9 percent of which were recorded in the first 17 days of April.

Saturday’s total puts Clallam County at 112 cases per 100,000, in territory that Berry said Friday could prompt serious consideration of stronger limitations on gatherings and restaurant occupancy. The positivity rate, at 5.3 percent, “continues to be high,” she said, adding that about 6,500 more residents need to be vaccinated to reach herd immunity.

In Jefferson County, Health Officer Tom Locke said Saturday 200-250 residents were administered the Johnson & Johnson vaccine, mostly through the Tri-Area Pharmacy in Port Hadlock and a recent “pop-up” clinic in Quilcene, a method of administering dosages to more people. Pop-up clinics could start soon in downtown Port Angeles with the help of the Port Angeles Chamber of Commerce, Berry said.

“If they need it the next day, we can make that happen,” chamber Executive Director Marc Abshire said Saturday.

Locke said three more cases of COVID-19 were reported Saturday, bringing the total to 368.

“Cases are definitely going up,” he said, pointing to the spread of virus variants, which he discussed Thursday at a county Board of Health meeting.

“We’re definitely in a fourth wave of the pandemic,” Locke said.

“We have to do it as well as we can to contain this,” he said. “It’s gonna be something that people who have been lax in their cautions against infection — who have gotten through a year of the pandemic without getting infected — they may find that that’s not so easy to do anymore,” he said. “Right now the hospitalizations are driven by the fact that we just have not been able to vaccinate the majority of people within this 18-to-50 age band.

“We’re still hopeful that if we do things right, this can largely be over by June.”

Locke said Saturday he believes the herd immunity that will signal effectively beating the virus will be reached when at least 70 percent of Jefferson County residents are fully vaccinated but that the actual percentage threshold is not really knowable. The full vaccination rate now is 39 percent in Jefferson County and 35 percent in Clallam.

Pfizer CEO Albert Bourla said last week that his company’s vaccine was effective after six months but that people may need booster shots within 12 months of getting vaccinated. The company studied six months of data.

Berry said that was unlikely and that there is limited data to make that determination.

“You can imagine there might be some motivation from Pfizer’s end to try to get more vaccine out that’s a little different than ours,” she said. “The only thing that would really trigger that is if we see large-scale variant activity of a variant that is resistant to the vaccine, which we have not yet seen.

“That’s part of the idea of why we are so intent on trying to cut back transmission.”

Locke said he believes there will be a one-year booster dose that will be recommended for everyone who received initial vaccinations.

“It could come before a year,” he said, adding research is being conducted to determine if it will be needed.

White House Advisor Dr. Anthony Fauci said on cnbc.com Thursday that people may need the booster shot.

“The way to get the answer is to just follow people closely enough to determine when that level of efficacy or protection diminishes, both with regard to the level of the antibodies as well as clinical data with regard to breakthrough infections,” Fauci said.

Breakthrough cases occur when vaccinated people who get COVID-19. Two breakthrough cases have been reported in Clallam County and none in Jefferson County.