A U.S. Centers for Disease Control and Prevention (CDC) advisory committee on Wednesday concluded a meeting to study the future of Janssen’s COVID-19 vaccine, manufactured by Johnson & Johnson (J&J), without daring to make a recommendation in the absence of data.
The CDC’s Advisory Committee on Immunization Practices (ACIP), composed of 15 independent experts, engaged in a four-hour discussion about the safety of J&J’s vaccine, which was developed by its Belgium-based division, Janssen, without reaching a conclusion.
On Tuesday, the CDC and the Food and Drug Administration (FDA), which approves vaccines, recommended a pause in the administration of the serum after six cases of a rare type of cerebral thrombosis were detected in women under 48 years of age who had been immunized with the preparation. One of the patients has died and another is in serious condition.
Despite being a recommendation, the announcement has caused a pause in the application of the vaccine through federal channels in the U.S., while the governors of several states in the country have decided to suspend it.
This Wednesday, the committee of experts met to decide whether or not to update the recommendation, although it finally decided not to do so and to wait for more data to issue an opinion in a week or ten days.
The group’s decision will help the U.S. government determine the next steps regarding the J&J vaccine.
During the session, the scientists debated whether to request that the suspension of J&J vaccination be continued or to apply it only to a certain age range, without reaching an agreement.
These discussions also brought to light the socioeconomic differences within the country, since this serum is the one being administered in the most disadvantaged and rural areas, as it is easier to store than those of the other vaccines authorized by the U.S., those of Pfizer and Moderna.
The experts also reviewed the cases of cerebral thrombosis detected and a representative of J&J revealed new data.
During the ACIP session, it was highlighted that headache would be the main symptom that the six women with cerebral thrombosis developed after receiving the J&J vaccine.
Tom Shimabukuro, a physician in charge of vaccine safety at the CDC, said that, apart from headache, five of these patients initially presented other mild symptoms, such as chills, apathy and myalgia, which later developed into severe headaches and abdominal pain, as well as swelling in one leg.
Meanwhile, according to J&J representative Aran Maree, Janssen’s chief medical officer, at least four of those six vaccinees were treated incorrectly with heparin, a drug that is usually used for thrombosis but is not recommended for the type of clots found after vaccination.
These cases include a 45-year-old woman who died; three women aged 38, 18, 48 who have not yet recovered; a 26-year-old woman, who is now well; and a 28-year-old woman, whose condition is unknown.
There is also a possible seventh case, a 59-year-old woman, who has presented with thrombi, but who does not fit the same profile as the others.
Maree added that during the clinical trials for the vaccine there was one volunteer, a 25-year-old man, who developed cerebral thrombosis after receiving the serum, although he has since recovered.
Another volunteer who was given a placebo also developed clots during the phase 3 trials.
Following the decision to recommend a suspension in the application of the vaccine, the U.S. Government insisted on Wednesday on the safety of the sera against covid-19.
This was emphasized by White House covid-19 response coordinator Jeff Zients, the government’s chief epidemiologist Anthony Fauci and CDC Director Rochelle Walensky at a press conference.
“Providing Americans with the facts they need to know is central to building confidence in vaccines,” Zients said.
The U.S. has given emergency use authorization to Pfizer and Moderna’s sera, which require two doses, and J&J’s serum, which is single-dose. AstraZeneca has not yet applied for such approval in the US.
The cases of adverse effects detected in the U.S. are similar to those reported in several European countries in AstraZeneca vaccinees, although CDC physician Beth Bell indicated during the ACIP meeting that the link between the thrombosis in vaccinees immunized with these two sera is not clear.
According to CDC data, 7.2 million doses of J&J’s vaccine have been administered to Americans so far, compared to 99.5 million doses from Pfizer and 85.4 million from Moderna.