A rare side effect from the one-shot Johnson & Johnson COVID-19 vaccine has caused health leaders in Santa Clara and San Mateo counties to pause its administration, they announced on Tuesday.
The decision follows a recommendation from the Centers for Disease Control and Prevention and the Food and Drug Administration to temporarily halt its use, county health officials said in separate statements today.
Although rare — only six cases out of about 7 million doses administered nationwide are known of the concerning side effects — CDC and FDA officials and the local authorities said they were halting the shots out of an abundance of caution.
The CDC and FDA are reviewing data involving a rare and severe type of blood clot after receiving the Johnson & Johnson vaccine, which is also known as the Janssen vaccine.
"In these cases, a type of blood clot called cerebral venous sinus thrombosis (CVST) was seen in combination with low levels of blood platelets (thrombocytopenia). All six cases occurred among women between the ages of 18 and 48, and symptoms occurred 6 to 13 days after vaccination. Treatment of this specific type of blood clot is different from the treatment that might typically be administered. 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," Dr. Anne Schuchat, the CDC's principal deputy director and Peter Marks, director of the FDA Center for Biologics Evaluation and Research, said in a joint statement on Tuesday.
Santa Clara County health officials said the county should be able to cover all scheduled appointments with the Pfizer-BioNTech or Moderna vaccines. County officials have also advised their vaccinating partners to pause administration of the Johnson & Johnson vaccine until further direction from the CDC, FDA and California Department of Public Health.
Dr. Marty Fenstersheib, the county's COVID-19 testing and vaccine officer, said on Tuesday afternoon that 62,000 people have received the J&J vaccine in Santa Clara County. He urged people to understand that the complications are "extremely, extremely rare" and typically appear six to 13 days after receiving the vaccine. They include a severe headache, abdominal or leg pain or shortness of breath. Anyone who has these symptoms should contact their health care provider or seek medical help, he said.
One of the six people who suffered a blood clot after getting the one-shot vaccine died, but no cases of complications from the J&J vaccine have been found in California, he said.
People who received the J&J vaccine more than a month ago have a very low risk of developing the symptoms, he added.
Dr. Jennifer Tong, assistant chief medical officer of the Santa Clara County Valley Medical Center, said the symptoms currently associated with the J&J vaccine can also be found in cases not associated with COVID-19 vaccination, so it is not yet known if there is a bona fide connection.
Dr. Anand Chabra, San Mateo County's COVID-19 vaccination branch chief, said in a Tuesday statement that the county will also pause all of its J&J vaccinations and has directed its partnering clinics and hospitals to suspend its administration until the vaccine is officially cleared by the CDC and FDA.
In San Mateo County, a total of 564,367 COVID-19 shots have been delivered by the county Health Department, health care providers and hospitals, pharmacies, community clinics and other partners. Of the total, 22,306 shots are of the J&J vaccine.
"This represents 3.952% of total vaccines administered in San Mateo County, the others being the Pfizer and Moderna vaccines," he said.
More than 5,700 doses of J&J vaccine have been used by the county Health Department and its vendors in mass-vaccination and community events for all eligible residents, homeless populations and homebound residents, in addition to other settings, he added.
"San Mateo County Health received 500 Janssen doses this week, which will be held pending further state and federal guidance," he said.
Community clinics that planned to use the J&J vaccine will be switched to Pfizer-BioNTech or Moderna vaccines, which are two doses given about three to four weeks apart, compared to the "one and done" J&J vaccine. Other vaccine programs that utilize J&J, including for the vaccination of homebound residents, patients discharged from hospitals and new bookings at correctional facilities, will be reevaluated, he said.
"The County does have some targeted events planned with J&J this week, but we have been able to supply those events with available Pfizer and Moderna doses so that those events can still take place at the same number of doses as planned," he said.
The CDC will hold a meeting of the Advisory Committee on Immunization Practices on Wednesday to further review the six cases and to assess their potential significance, the federal authorities said.
"FDA will review that analysis as it also investigates these cases. Until that process is complete, we are recommending a pause in the use of this vaccine out of an abundance of caution. This is important, in part, to ensure that the health care provider community is aware of the potential for these adverse events and can plan for proper recognition and management due to the unique treatment required with this type of blood clot.
"Right now, these adverse events appear to be extremely rare. COVID-19 vaccine safety is a top priority for the federal government, and we take all reports of health problems following COVID-19 vaccination very seriously. 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."
Health care providers are asked to report adverse events to the Vaccine Adverse Event Reporting System.
Find comprehensive coverage on the Midpeninsula's response to the new coronavirus by Palo Alto Online, the Mountain View Voice and the Almanac here.