Oregon has paused using the Johnson & Johnson one-shot COVID-19 vaccine even though none of six newly reported severe reactions to the vaccine occurred in the state, health officials said Tuesday.

The U.S. Centers for Disease Control and Prevention urged states to temporarily stop using the vaccine given to 6.8 million people after six women who received the vaccine became seriously ill and one died.

“This appears to be extremely rare,” Dr. Paul Cieslak, Oregon Health Authority’s medical director for acute and communicable disease and immunizations, said during an afternoon press call.

The CDC said the six women were aged 18 to 48. They became ill from one to three weeks after their vaccination. The cause appeared to be a rare blood clot disorder.

The state has given about 82,000 Johnson & Johnson shots, a tiny fraction of the 2.3 million vaccine doses administered since December. OHA said about 212,000 doses are on hand in 225 locations around the state and can be kept in regular refrigeration units for later use when federal officials lift the advisory.

Johnson & Johnson vaccines are no longer administered at the mass vaccination center at the Deschutes County Fair & Expo Center in Redmond.

Mosaic Medical, which has 15 clinics serving 27,000 patients in Central Oregon, said in a statement it was temporarily pausing use of the Johnson & Johnson vaccine in alignment with OHA and CDC recommendations.

“We have received several calls from Mosaic patients who have received the J&J vaccine, and we are sharing with them the information that the events under investigation are extremely rare — out of more than 6.8 million people who have received the J&J vaccine in the U.S., six have developed a rare but serious type of blood clot,” said pharmacy services director Albert Noyes. “If the patient has received the J&J vaccine in the past three weeks and is experiencing severe headache, blurred vision, abdominal pain, leg pain or shortness of breath we will connect them immediately with emergency medical services, or their provider when appropriate, for further evaluation.”

Noyes also said mild headache and flu-like symptoms 24 to 48 hours after vaccination are common and expected symptoms related to immune response.

Cieslak said severe symptoms include pain in the legs — which could indicate a blood clot — severe headache and abdominal pain. Anyone experiencing the symptoms should contact a doctor or local public health agency. Information is also available by calling 211.

There have been no reports of any similar severe side effects to the Moderna and Pfizer two-shot vaccines.

Federal health officials will begin meeting Wednesday to look at the data on the severe cases and see if there is a direct connection between the vaccine and the illnesses.

Dr. Janet Woodcock, acting commissioner of the Food and Drug Administration, said Tuesday during a press conference in Washington, D.C., that a review of the vaccine would likely be “a matter of days.”

Cieslak said the state would resume using the one-shot vaccine as soon as it gets “a green light” from federal officials.

The halt in using Johnson & Johnson vaccines will not change plans to open up vaccine eligibility to everyone age 16 and older on Monday. Availability has lagged eligibility throughout the vaccination priority phases and the same is expected to occur next week.

“People will have to wait a little longer” to get vaccinated, Cieslak said.

Oregon officials had already been bracing for a steep drop in available doses of the vaccine due to a botched batch of 15 million doses that had to be destroyed at a Baltimore facility.

Oregon received over 60,000 doses last week, but the breakdown in the supply chain due to the mishap in Baltimore reduced the flow to 8,000 this week and down to 2,000 next week.

OHA reported Tuesday that 928,874 Oregon residents have been completely inoculated, mostly with the two-shot Moderna and Pfizer vaccines. Another 539,753 people have received their first dose of a two-shot vaccine. The second shots are given three to four weeks after the first.

OHA has estimated that up to 3.2 million Oregonians are 16 and older, the age group currently approved as safe to vaccinate. Several research efforts into a vaccine for children are underway, but none has been given federal approval.

Asked if the pause would fuel vaccine hesitancy among Oregonians, Cieslak said that those predisposed to not be vaccinated will likely latch on to the issue.

“There are some people who are going to decline vaccination regardless,” he said. “If they were thinking vaccinations were harmful anyway, this will give them additional fuel.”

But the pause was actually a way to show the public that serious reactions, no matter how tiny a percentage, will be investigated. He expects the Johnson & Johnson vaccine to be back in use relatively soon. Whatever vaccine is available, he encouraged residents to sign up.

The vaccines are “effective on a disease that has killed a lot of people,” he said.

Gov. Kate Brown was inoculated with the Johnson & Johnson vaccine March 6 to show the state’s confidence in the vaccine. She has reported no side effects. The vaccine was also given to several lawmakers and staff during an April 7 clinic in Salem.

COVID-19 has infected 31.2 million people in the United States and caused over 562,000 deaths, according to the Johns Hopkins Coronavirus Resource Center.

Oregon has had one of the lowest infection and death rates in the country, with OHA reporting 171,398 positive cases through Tuesday and 2,446 deaths.

Infections have been on the rise again over the past few weeks after a long decline following the peak levels of January.

Most of the deaths throughout the pandemic have been in adults 70 and older. About 75% of that population in Oregon has now been vaccinated.

The high immunization level of those most vulnerable to severe illness and death from COVID-19 has slowed hospitalizations and deaths during the current rise in overall infections.