Following federal guidance, Washington health care providers are temporarily pausing Johnson & Johnson shots while experts educate hospital systems on how to treat a rare side effect that may be linked to the single-dose vaccine.

Of the nearly 7 million people nationwide who have received the Johnson & Johnson vaccine, officials have identified six cases of brain blood clots.

“This action is being taken out of extreme caution,” said state Secretary of Health Dr. Umair Shah during a news conference. “This rarity of a side effect, one in a million, while it is serious, it has to be reminded to people that this is rare.”

On April 14, a federal vaccine advisory group will review the blood clot cases. Johnson & Johnson shots could resume in a matter of days, Shah said.

The pause, he added, gives officials time to tell doctors to avoid prescribing Heparin, a blood thinner, to treat the side effect.

In many cases, the drug is used to prevent blood clots. But in this instance, it could cause severe damage, Shah said.

For those who got the vaccine more than a month ago, the risk of this complication is very low, the state Department of Health said in a news release.

“People who have received the J&J vaccine who develop severe headache, abdominal pain, leg pain, or shortness of breath within three weeks after vaccination should contact their health care provider,” the agency said. “It also demonstrates how well the robust vaccine safety monitoring systems work, since this potential safety concern was identified quickly and vaccines were paused to allow for further investigation.”

Public Health – Seattle and King County also released a statement in response to the decision.

“The J&J vaccine provides great benefits in protecting people from serious COVID-19 infections,” said Dr. Jeff Duchin, health officer. “National vaccine safety monitoring systems have identified an association between this vaccine and a rare type of serious blood clotting disorder. This safety signal has not been identified with the mRNA vaccines made by Pfizer and Moderna. Over the coming days, we will have more information about the risk of this rare event after vaccination in relation to the benefits of vaccination, including risk related to age and gender, and whether any changes are needed in how we use the J & J vaccine.”

People who signed up will now receive a Pfizer dose, and be scheduled for a second appointment in three weeks.

Across Washington, Johnson & Johnson’s vaccine makes up about 6% of the state supply.

The pause comes two days before the state expands vaccine eligibility to everyone 16 and older.

How this will impact vaccine distribution in King County

The King County health department reports:

• Auburn high-volume vaccination site at the Auburn Outlet Mall: Anyone who currently has an appointment scheduled at the Auburn Outlet Mall vaccination site can keep their appointment and receive the Moderna vaccine instead of J&J. The Auburn site has paused scheduling new appointments.

• Kent high-volume vaccination site at ShoWare Center: Appointments at the Kent vaccination site use the Pfizer and Moderna vaccines and are not affected.

• Community partner vaccination sites: Several thousand J&J doses were distributed to community partners by Public Health this week. Public Health has contacted them to pause administering J&J vaccines and await further information.

• City of Seattle community vaccination fixed sites: All currently scheduled appointments will remain scheduled using the Pfizer vaccine.

• Mobile vaccination: Public Health’s planned mobile vaccine visits to homeless service sites and homebound individuals will use Moderna vaccine instead of J&J.

King County jails: Vaccination is currently paused.