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SAN DIEGO — San Diego County is pausing use of the Johnson & Johnson coronavirus vaccine following guidance from the federal government, officials said Tuesday.

The U.S. Centers for Disease Control and Prevention and the Food and Drug Administration recommended states pause use of the one-dose vaccine after six women between the ages of 18 and 48 developed a “rare and severe” blood clot called cerebral venous sinus thrombosis, according to a joint statement from the agencies.

The women developed the clot six to 13 days after receiving a Johnson & Johnson vaccine.

“This will be a minor disruption for folks who had J&J appointment but the number of J&J vaccines in San Diego is exceedingly low,” County Board of Supervisors Chairman Nathan Fletcher said. “I think nationally it’s been about 3% of the total and that probably tracks around here locally.”

Cerebral venous sinus thrombosis is a form of blood clot that typically occurs in younger patients, usually under 50 years old and predominantly women, according to the county Health and Human Services Agency.

According to the CDC, CVST occurs in anywhere from 5 to 16 people per 1 million people per year in the United States.

Around 6.85 million doses of the Johnson & Johnson vaccine have been administered in the United States, including about 58,000 San Diegans. No known severe adverse effects have been reported in the region.

“The cases that prompted the pause appeared in the Vaccine Adverse Event Reporting System,” said Dr. Wilma Wooten, San Diego County’s public health officer. “The fact that the six cases of a rare condition were identified after recent vaccination followed by a pause while further investigations occur is a sign that the system works.”

The CDC and FDA use the reporting system to collect reports from health care professionals, vaccine manufacturers and the public of adverse events that happen after vaccination. Reports of adverse events that are unexpected, appear to happen more often than expected or have unusual patterns are followed up with specific studies.

For San Diegans who got the vaccine more than a month ago, the risk to them is very low at this time, officials said. For San Diegans who recently got the vaccine — within the last few weeks — they should be aware of any symptoms.

Those who have received the vaccine and develop severe headache, abdominal pain, leg pain or shortness of breath were urged to contact their health care provider and seek immediate medical treatment.

“What I have been conveyed to me is, we’re talking less than one in 1 million that had any situation,” Fletcher said. “But if anyone has any concerns, reach out to your health care provider.”

A city spokesperson said San Diego Fire-Rescue also paused the administration of the one-dose COVID-19 vaccine and Cal Fire appointments for J&J doses will be filled using the Pfizer vaccine.

The federal authorities said in a joint news conference Tuesday that they expect the pause to last “a matter of days.”

The Associated Press reports cases appear similar to a rare type of clotting disorder European authorities say possibly is linked to AstraZeneca’s vaccine, which is not yet cleared in the U.S.

The CDC will convene a meeting of the Advisory Committee on Immunization Practices on Wednesday.