Federal authorities have lifted a "pause" on the use of the Janssen/Johnson & Johnson vaccine, potentially opening thousands of appointments for COVID-19 shots in the coming weeks.
The Centers for Disease Control and Prevention and Food and Drug Administration announced the removal of the pause on April 23, noting that the concerning adverse effects have affected only 15 people out of 6.8 million doses.
The federal agencies recommended the pause on April 13 after six women developed rare blood clots, or thrombosis involving the cerebral venous sinuses — large blood vessels — in the brain. All of the cases occurred in women between the ages of 18 and 59, with a median age of 37 years. Symptoms began between six and 15 days after vaccination, the CDC noted.
The stay was lifted after a thorough scientific review determined that the benefits of the Janssen vaccine outweigh the risks.
The federal agencies assessed reports submitted to the Vaccine Adverse Event Reporting System, reviewed information about some similar adverse effects in another vaccine that uses a modified inactive virus from the adenovirus family. The Astrazeneca vaccine, which is similar but not identical, was also modified to contain the gene for making a protein from SARS-CoV-2, the virus that causes COVID-19 infections.
The agencies plan to continue monitoring the J&J vaccine for adverse effects, they said.
"We are confident that this vaccine continues to meet our standards for safety, effectiveness and quality," CDC and FDA officials said in a press release on Friday. The vaccine doses will come with a new warning label and a fact sheet that warns of the rare blood clots.
In California, as an additional safeguard, the Western States Scientific Safety Review also will examine the vaccine and make recommendations to the state Department of Public Health.
In a joint statement over the weekend, the health officers for Alameda, Contra Costa, Marin, Napa, San Francisco, Santa Clara, Santa Cruz and Solano counties and the city of Berkeley said they concur with the findings that "the Johnson & Johnson vaccine is safe and that Bay Area health providers should resume its administration to prevent community spread and severe illness and death from COVID-19."
"The region's health officers agree that the risk of developing the rare clotting disorder is extremely low," they said. "(We) also support the addition of a warning label and the WSSSR's recommendation that culturally and linguistically appropriate informational materials in an accessible reading level be made available, so that the members of the public can make an informed decision."
"People who have received the Johnson & Johnson vaccine should contact their primary healthcare provider if they have concerns or if they develop severe symptoms of headache, abdominal pain, leg pain or shortness of breath within three weeks after vaccination," they added.
The single-dose Johnson & Johnson vaccine was considered an important component in getting shots in the arms of residents, particularly those who might balk at the two-shot regimen, which is given about 21 to 28 days apart. The vaccine also was considered an important breakthrough for people who are homeless or are homebound and can't easily access the two-shot regimen, county officials have said. The Janssen vaccine is also stored at higher freezer temperatures than the Pfizer and Moderna vaccines, facilitating its distribution without need for more specialized freezers.
Editor's note: Pleasanton Weekly editor Jeremy Walsh contributed localized information to this story.