A group of advisers to the Centers for Disease Control and Prevention said vaccinations with Johnson & Johnson's coronavirus shot should be resumed in the U.S., deciding in a Friday meeting that updated labeling would be sufficient to alert healthcare providers and the public to the risk of a rare but serious side effect.
The advisers voted 10-4 in favor of the recommendation, clearing the way for the CDC and Food and Drug Administration to lift their recommended pause on vaccinations just two hours later.
"We have concluded that the known and potential benefits of the Janssen COVID-19 Vaccine outweigh its known and potential risks in individuals 18 years of age and older," said Janet Woodcock, acting Food and Drug Administration commissioner, in a statement.
The drugmaker and the FDA had previously agreed on the wording of the warning, which was added to the shot's prescribing information but not as a restriction on its use.
Advisers on the panel were eager to see use of the vaccine resumed, citing its efficacy and overall safety. But there was some disagreement over how strongly to warn the public about an unusual syndrome involving dangerous blood clotting near the brain.
"I can live with this recommendation," said Beth Bell, a clinical professor in global health at the University of Washington and a CDC adviser. But Bell noted she was concerned that younger women, who appear most at risk, "will not be adequately informed" by the fact sheet given to vaccine recipients and providers.
"So we really are depending on the public health agencies and the partner organizations to make sure that people actually are informed and that they are empowered and that they actually get a balanced perspective." She voted in favor of the panel's recommendation.
Vaccinations have been suspended since April 13, when regulators at CDC and the FDA reported six women given J&J's shot experienced the abnormal clots alongside low levels of platelets, the sticky cells that help blood coagulate. Although extremely rare, the unusual combination of symptoms is potentially life-threatening. Moreover, health officials had feared physicians, unaware of the specific syndrome, would turn to treatment that could make patients' condition worse.
At a meeting Friday, CDC officials documented nine more cases, bringing the total confirmed in the U.S. to 15. All were in women, with 13 in women aged 18 to 49 years. Three have died and seven remain hospitalized, with four still in intensive care.
Nearly 8 million people had received J&J's vaccine through Wednesday. Because blood clotting near the brain occurring alongside low platelets is so unusual, health officials could only give a rough estimate of how frequent such events would typically be outside of vaccination. But the incidence associated with J&J's vaccine appears higher than what would be expected, particularly so in younger women, CDC presentations showed.
CDC officials showed data indicating the reporting rate of the condition, termed thrombosis with thrombocytopenia syndrome or TTS, was about seven cases per every 1 million women aged 18 to 49 who had received J&J's shot. That estimate could change, however, should more cases be identified or more vaccines be administered. Several cases are currently being reviewed, one of the officials, Tom Shimabukuro, said.
The officials and their advisers spent considerable time weighing that risk against the benefits of J&J's vaccine, which is given via one dose and viewed as more convenient for harder-to-reach populations. A large clinical trial showed in January the shot protected against moderate or severe COVID-19 and was effective, albeit somewhat less so, against a virus variant first identified in South Africa.
For every 1 million vaccinations of women aged 18 to 49, for example, the CDC estimated 12 deaths and 127 intensive care unit admissions would be prevented.
"We need as many people to be vaccinated as possible in order to reach community immunity and put the pandemic behind us," said Henry Bernstein, a professor of pediatrics at the Zucker School of Medicine at Hofstra/Northwell and member of the CDC panel. "The J&J vaccine will help us do just that."
The decision to pause vaccinations was a forceful and much debated measure by regulators. At an April 14 meeting, held one day after the pause, the same group of CDC advisers had expressed concern about the risks of suspending immunizations given the continued high levels of transmission and COVID-19 cases in the U.S. But they chose to postpone a vote on revising recommendations, citing lack of data on the true risk of TTS.
On Friday, FDA and CDC officials reiterated their belief the decision to pause was the right one. Melinda Wharton, director of the CDC's immunization services division, noted the suspension raised awareness about the side effect and allowed regulators to alert clinicians on how to recognize and treat it.
"I think there was a very important objective achieved by the pause," Wharton said.
By voting to resume vaccinations without restriction, the panel's decision mirrored the response from European regulators, which added warning language to J&J's shot earlier this week.
Authorities in Europe also took a similar approach to a vaccine from AstraZeneca, which in early April they linked to a syndrome that closely resembles the TTS reported with J&J's shot. A wave of European countries had paused vaccinations with AstraZeneca's product following reports of the condition, although most have since resumed.
In that case, the European Medicines agency added a warning to AstraZeneca's vaccine but opted against restriction use by age.
In the U.S., vaccinations have proceeded apace since April 13 as increasing supply from Pfizer and Moderna of their respective vaccines has allowed states to broaden availability despite lacking J&J's vaccine. More than a quarter of American adults are now fully vaccinated and 137 million have received at least one dose.
The panel's recommendation Friday and likely rapid resumption in vaccinations with J&J's shot should unlock an influx of millions of doses that were produced and in distribution at the time of the pause. But subsequent supply of the vaccine is likely to be unsteady as a major mix-up at a contractor's plant in Baltimore has hamstrung further manufacturing. The FDA requested the contractor, Emergent Biosolutions, pause all production.
J&J has contracted to provide the U.S. with 100 million doses by the end of June, but it's not clear whether the country will end up needing anywhere near that number.
Note: This story has been updated with additional detail and commentary.