The U.S. Centers for Disease Control and Prevention recommended messenger RNA vaccines made by Moderna Inc. and Pfizer Inc. for use in adults over Johnson & Johnson’s shot, which has been linked to rare but serious blood clots.
All 15 members of CDC’s Advisory Committee on Immunization Practices voted in favor of the recommendation Thursday after U.S. regulators announced revisions to the shot’s fact sheet to warn of the rare clotting syndrome. CDC Director Rochelle Walensky signed off on the advice.
“Today’s updated recommendation emphasizes CDC’s commitment to provide real-time scientific information to the American public. I continue to encourage all Americans to get vaccinated and boosted,” she said.
Vaccines and boosters are becoming increasingly important as omicron spreads across across the world. While delta remains the dominant strain in the U.S., omicron has now been detected in 33 states, and has quickly risen to account for an estimated 3% of cases nationally, although it may be far more prevalent in New York and New Jersey, the CDC has said.
The risk of the vaccine-linked condition, called thrombosis with thrombocytopenia syndrome or TTS, may be higher than previously thought. The rate among women with TTS as of early December was 5.84 per million J&J doses administered, compared with 4.85 in mid-June, according to a presentation at the meeting.
Women ages 30 to 49 were at the highest risk of the syndrome and resulting death, according to the presentation from Isaac See of CDC’s Covid Vaccination Safety Task Force. Men of all ages who received the vaccine had a lower risk of the complication.
However, the risk of rare forms of blood clotting is exponentially greater from Covid-19 itself than from a single dose of the J&J vaccine, said Penny Heaton, the head of vaccines for the company’s Janssen pharma unit. Citing research from the University of Oxford, Heaton said Covid causes more than 400 cases of the rare events per 1 million people.
J&J remains confident that its vaccine’s benefits outweigh its risks, according to a statement. Studies have shown the shot “generates strong antibody and cellular immune response and long-lasting immune memory and breadth of protection across variants,” the drugmaker said.
“The safety and well-being of those who use the Johnson & Johnson vaccine continues to be our number one priority,” said Mathai Mammen, global head of R&D for the Janssen unit. J&J shares rose 1.1% at the close of trading in New York.
The J&J shot was once expected to be central to the U.S. vaccination campaign. The one-shot vaccine keeps in a refrigerator and was seen as a tool to immunize hard-to-reach populations. However, mRNA shots from Moderna and the partnership of Pfizer and BioNTech SE performed better in trials and are more widely used.
Rescinding the recommendation for J&J or restricting it to specific groups could lead to equity concerns for the homeless, homebound, and incarcerated, CDC Epidemic Intelligence Service Officer Sara Oliver said in a presentation. People who travel frequently, lower-income communities, temporary agricultural workers, and socially-isolated individuals might also suffer from lack of access to the vaccine, Oliver said.
But some panel members were highly concerned by the risks of the J&J shot, and asked for stronger language than “preferred” in the recommendation.
“I just cannot recommend a vaccine that is associated with a condition that may lead to death,” said Pablo Sanchez, a pediatric infectious disease specialist from Ohio State University. “I am not recommending it to any of my patients.”
In April, U.S. health agencies urged providers to stop administering the shot to assess rare blood clots occurring among some recipients, primarily young women. Regulators lifted the pause after 10 days, suggesting that the chance of developing the rare blood clot syndrome was very low, and the benefits of the shot outweighed the risks.
At the time, ACIP members voted to stick to recommending the J&J vaccine to all adults, but included the FDA’s new warning statement about the risk of clots with the shot for women under 50.
The vast majority of vaccinated Americans have received either a Pfizer-BioNTech or Moderna mRNA shot. Pfizer and BioNTech asked the U.S. Food and Drug Administration to approve their shot for teens ages 12 to 15 Thursday; it’s current cleared for the age group by an emergency-use authorization.
J&J’s shot accounts for just 3%, or about 17 million, of the 488 million doses administered in the U.S., according to CDC data. Around 880,000 J&J booster doses have been administered.