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A panel that advises the Centers for Disease Control and Prevention gave a rare preferential recommendation to the Covid vaccines based on messenger RNA technology on Thursday — a decision aimed at steering people away from the Johnson & Johnson Covid-19 vaccine because of concerns about a rare but serious side effect.

The recommendation passed by a unanimous vote, with all 15 members of the Advisory Committee on Immunization Practices supporting it.


The recommendation levels another blow to J&J’s vaccine, which has struggled to find a foothold in the U.S. market. Within hours, CDC Director Rochelle Walensky accepted the recommendation.

“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,” Walensky said in a statement.

A preferential recommendation still leaves the choice of vaccine to the individual getting vaccinated. But it will likely further depress the already limited demand for this vaccine in the U.S. market.


The decision was based on additional evidence of cases in the U.S. of a dangerous clotting condition known as thrombosis with thrombocytopenia syndrome, or TTS, a side effect that has been seen with the J&J and AstraZeneca vaccines. Both vaccines use a genetically modified cold virus called an adenovirus that carries instructions for making the SARS-CoV-2 spike protein. Doran Fink, deputy director of the Food and Drug Administration’s Division of Vaccines and Related Products Applications, described TTS as a “class effect” — meaning it is common to vaccines made this way.

The committee was told that 54 cases of TTS after receipt of the J&J vaccine have been reported in the U.S. to date. Nine of those people have died and another two deaths are suspected to have been linked to the vaccine. About 17 million doses of the vaccine have been used in the United States.

Cases of vaccine-related TTS have been seen in both women and men and across a variety of age groups. But the highest rate is among women in their 30s and 40s. In that age group, there have been approximately two deaths from TTS per 1 million doses of J&J vaccine administered.

The ACIP’s move is not unique: A number of other countries have restricted use of the J&J and AstraZeneca vaccines as a consequence of the TTS risk. (Although it tested its vaccine in the U.S., AstraZeneca has not pursued an authorization from the Food and Drug Administration.)

The committee was presented with a number of options by CDC staff, including the possibility of recommending discontinuation of the J&J vaccine. During the discussion, a couple of members of the committee acknowledged they have actively discouraged family members or patients from choosing the vaccine.

But it was clear from the discussion that the committee members were aware that moves the U.S. takes are closely watched abroad. Had the group decided to recommend against further use of the vaccine in this country, it likely would have decreased willingness of some countries that are relying on the vaccine to use it.

“I believe that we should really keep in mind that our decision does or likely will have a global impact,” said committee member Oliver Brooks, the chief medical officer for Watts Healthcare Corporation in Los Angeles.

Penny Heaton, global head of vaccines for Janssen, J&J’s vaccines division, sounded angry at times while addressing the committee. She stressed that the vaccine continues to prevent illnesses and deaths.

“While TTS continues to be a rare event, unfortunately cases of Covid-19 are not,” Heaton said, adding that studies have shown that clotting events like those linked to the vaccine happen at a higher rate among people who contract the virus.

Less than 4% of vaccinated Americans have chosen to receive the J&J vaccine, which was approved as a one-dose option. Earlier this autumn the FDA and the CDC said that people who had received the J&J vaccine should get a second dose of Covid vaccine — from the manufacturer of their choosing — two months after their first dose. People who receive that Pfizer and Moderna vaccines have to wait six months for booster doses.

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