San Mateo Co. Halts J&J Vaccine Use, 500 Doses On Hold

REDWOOD CITY, CA — San Mateo County will temporarily pause the use of the Johnson & Johnson vaccine after a handful of serious blood clotting cases were reported across the U.S., officials said in a statement Tuesday.

The county received 500 doses of the single-shot vaccine this week, but all doses will be held as officials wait on further guidance from the state and federal government.

The news comes after the federal government recommended an immediate pause in the use of the Johnson & Johnson vaccine nationwide Tuesday after six people — all women between 18 and 48 — developed serious blood clots 6 to 13 days after being inoculated.

One woman died, and a second woman in Nebraska was hospitalized in critical condition.

Within San Mateo County, a total of 22,306 Johnson and Johnson shots have been received locally, representing nearly 4 percent of all vaccines administered, officials said. More than 5,700 of those doses were used at mass vaccination sites, community events, for homeless populations and other settings.

"County Health has also directed its vaccinating partners, including hospitals and local clinics, to suspend use of the Janssen vaccine until it is officially cleared by CDC/FDA," Dr. Anand Chabra, the county's vaccination branch chief said in a statement.

All community clinics that had planned to use the J&J vaccine will switch to Pfizer or Moderna, county officials said. Other initiatives that were solely using the vaccine in question — including vaccinating homebound residents, patients discharged from hospitals and new bookings at correctional facilities — will be reevaluated, officials said.

County officials anticipate that vaccination events will still go on as planned at that all J&J vaccines will be replaced with available Pfizer and Moderna doses.

READ MORE: Johnson & Johnson Vaccine Pause: 6 Things To Know

Other Bay Area counties — Alameda, Contra Costa, San Mateo and Marin — also announced that use of the vaccine would be placed on pause, pending federal guidance.

Although federal officials are urging that adverse reactions to the vaccine "appear to be extremely rare," authorities are reviewing the six cases, which involved "cerebral venous sinus thrombosis in combination with low levels of blood platelets."

"Treatment of this specific type of blood clot is different from the treatment that might typically be administered," federal officials said on Tuesday. "Usually, an anticoagulant drug called heparin is used to treat blood clots. In this setting, administration of heparin may be dangerous, and alternative treatments need to be given."

More than 6.8 million doses of the J&J vaccine have been administered in the U.S.

The CDC will convene a meeting of its Advisory Committee on Immunization Practices on Wednesday to further review the cases and assess their potential significance.

Dosage supply was predicted to crater by about 15 percent in the Golden State this week following a previous shortfall in the production of the Johnson & Johnson vaccine — and now that number could fall even more.

Production of the vaccine was temporarily halted last week amid issues with a manufacturer in Baltimore.

Still, Gov. Gavin Newsom said Tuesday that "vaccines are still overwhelmingly safe. We're vaccinating 3+ million people a week and are still on track to fully reopen."

Newsom himself received the Johnson & Johnson shot on April 1.

SEE ALSO: CA Halts Use Of J&J Vaccine Amid Blood Clot Reports