After hearing hours of testimony on the risks and benefits of Johnson & Johnson’s single-dose Covid-19 vaccine, a panel of experts voted in favor of its continued use for all adults despite concerns over blood clots.
WASHINGTON (CN) — An independent advisory panel for the U.S. Centers for Disease Control and Prevention voted Friday to recommend the continued use of the Johnson & Johnson Covid-19 vaccine after the single-dose jab was put on pause over blood clotting concerns.
The 10-4 vote, with one abstention due to a conflict of interest, was held during a meeting of the CDC’s Advisory Committee on Immunization Practices. Last week, the CDC and Food and Drug Administration recommended a temporary halt to states’ use of the J&J treatment after six cases of blood clots were detected among over 6.8 million people who got the shot. The U.S. announced the purchase of 100 million doses last month, most of which have been sitting in storage since the decision to pause it.
The CDC and FDA still have to approve the panel’s recommendation before the J&J shot can be used again in clinics, but that authorization could come as soon as next week. The panel advised adding a warning label about an increased risk of rare but serious blood clots.
Friday’s vote followed similar worries in the Europe Union over both the J&J jab and the AstraZeneca vaccine, which also faced concerns over blood clots. Like AstraZeneca, the European Medicines Agency found a link between the J&J vaccine and very rare cases of blood clots, but said its benefits far outweigh the risks. EU member states began administering the shot this week.
The EU data was shared with U.S. researchers as both of the treatments use a similar delivery system, different from the two-dose Moderna and Pfizer shots which have reached hundreds of million arms since January with no known link to clotting, according to CDC experts.
The panel vote was held after a daylong public meeting that included input from a variety of private and state scientists who discussed where the blood clotting issue – known as thrombosis with thrombocytopenia syndrome, or TTS – was first detected, treated and how it was found in the states.
Dr. Michael Streiff with Johns Hopkins University School of Medicine specializes in blood clotting and coagulation research. He said the usual appearance of the TTS clotting issue occurs in about one per 10 to 15 million people.
“It’s quite a rare event,” he told the panel Friday. “So this is far rarer than [other thromboses] we see on an annual basis.”
In the U.S., six blood clot cases were found before the J&J vaccine was paused. Additional research found a total of 15 cases, all among women, with few links between patients. Three of them died, seven remain hospitalized and five were released from treatment.
“We recommended a pause [on April 14] out of an abundance of caution while further assessment could occur,” said CDC researcher Dr. Tom Shimabukuro, who also testified before the panel. “Health care providers should be aware of these potential events and offer treatments for these kinds of blood clots”
Shimabukuro said another 140,000 J&J doses were administered through April 17 and no TTS cases were detected, but 22 other blood clotting issues were.
“We had a small number of thrombosis but none of the TTS,” he said. “TTS is rare but clinically serious. It’s been observed in association with the J&J… it’s similar to what’s been observed with AstraZeneca in Europe. And the US system is able to rapidly detect the adverse events.”
The scientists also said the CDC had medical guidance for health care providers to treat and test for the issue. Additionally, the agency promised to continue to monitor the issue, including expanding the search strategy to check other possible clotting incidents related to vaccine doses.
Beyond the 15 known cases, Shimabukuro said about 10 additional cases were under review for possible TTS, but “it’s a dynamic number right now.”
Dr. Mathai Mammen, the global head of research and development for Janssen, the German company that owns J&J and produced the vaccine, also spoke during the meeting.
“We believe the J&J vaccine has important and even unique benefits in our effort to end the global pandemic of Covid-19,” he said before stressing the single-dose nature, and its ability to be stored for months in normal refrigerated conditions, was a benefit for those with limited access. It could help slow the spread of variants that have begun to take hold in the U.S. after developing overseas.
“It’s the only practical option for some people,” Mammen said. He called TTS occurrences “very rare, but a very important and serious risk.” He recommended including a warning label and staying ahead of incidents to help address them as they arise.
“Our goal is earlier recognition and improving outcomes in these rare events,” he added.
Dr. Joanne Waldstreicher, Johnson & Johnson’s chief medical officer, emphasized the rarity of TTS occurrences in the context of the benefits the vaccine can provide.
“If 1 million people were vaccinated with the J&J, there would be 2,000 fewer deaths and 6,000 fewer hospitalizations with two additional TTS cases,” she said. “We believe the J&J vaccine is essential to ending the pandemic.”