For the past several months, one of the many questions hanging over the booster debate has ben what do with people who got J&J’s shot. The company’s application, and the FDA’s planned meeting, creates a timeline for answering that question.
Biden administration and public health officials drew on data from extensive real-world use of Pfizer’s and Moderna’s vaccine in the U.S., as well as from Israel’s rollout of Pfizer boosters, to inform their plans for additional messenger RNA doses.
But there was comparatively less data to go on for J&J’s vaccine, which ended up sparingly used after manufacturing and safety setbacks early this year. Experts also questioned whether the more modest efficacy observed in clinical testing of one dose of J&J’s vaccine might mean recipients were now less protected.
At a Sept. 23 meeting of advisers to the Centers of Disease Control and Prevention, committee members voiced concerns that people vaccinated with the J&J shot were being “left out” as they moved ahead with recommending Pfizer boosters.
“I just don’t understand how … we can say to people 65 and older, ‘You’re at risk for severe disease and death, but only half of you can protect yourself right now,'” said Sarah Long, a member of the CDC advisory panel and professor at Drexel University College of Medicine, discussing a vote that applied only to people vaccinated with Pfizer’s shot.
J&J’s release late last month of summary data from a large study testing two doses of its vaccine now gives regulators information to act on. The results, which have not yet been published, showed an additional shot, given eight weeks after the first, resulted in an estimated 75% protection against moderate to severe COVID-19, compared to placebo.
The efficacy findings were also supported by data indicating a second dose boosted antibody levels four- to six-times higher when given two months after the first, and between nine- and 12-times higher when given six months after the first.
Even so, it’s not clear for how long a booster would improve protection. Detailed information about its safety is also lacking.
In addition to the FDA, J&J is planning to submit data on a booster dose to other regulators and the World Health Organization.
At the Oct. 15 meeting, FDA advisers will also discuss so-called heterologous boosting, or using one vaccine as a booster dose for another, such as giving a dose of Pfizer’s shot to people who previously received J&J’s.