It was a busy weekend for Johnson & Johnson’s single dose COVID-19 vaccine, which received emergency use authorization (EUA) from the FDA on Saturday, and was authorized the next day by CDC under the EUA’s terms.
CDC’s Advisory Committee on Immunization Practices (ACIP) voted 12-0 (with one abstention) to recommend it for adults ages 18 and older. Shortly afterwards, CDC director, Rochelle Walensky, MD, announced the official CDC backing.
On Sunday night, senior White House officials gave a briefing on background, where they said distribution of 3.9 million doses of the J&J vaccine would begin immediately, with actual administration possible as early as Tuesday morning. The company expects to deliver about 16 million additional doses by the end of March, officials said.
This vaccine will be allocated in the same manner as the Pfizer/BioNTech and Moderna vaccines, officials said, which is proportional to a state, tribe or territory’s population. CDC will also be monitoring distribution of vaccines across a range of metrics, including zip codes and the Social Vulnerability Index.
At a media briefing Saturday night, acting FDA Commissioner Janet Woodcock, MD, reiterated issues raised by the FDA advisory committee on Friday, that the J&J product’s lower efficacy number (70% vs 95%) may lead people to believe it’s less effective than the others. She said that wasn’t necessarily so and urged Americans to “take the vaccine they are able to access.”
“All these vaccines meet our standards for effectiveness. They were not studied in head-to-head trials, so [they’re] difficult to compare … due to differences in development programs,” she said. (For one thing, efficacy in the J&J trial was judged for preventing moderate-to-severe COVID illness, whereas the endpoint was all symptomatic COVID in the Pfizer and Moderna studies.)
At the ACIP meeting, committee members raised the issue of potentially comparing the vaccines, but chair Jose Romero, MD, said that was not their task for today, but they could discuss it when ACIP meets again on Monday.
“We need to be clear on our messaging regarding comparisons with other vaccines,” said Jason Goldman, MD, of the American College of Physicians. “As a primary care physician, many of us are eager to vaccinate” patients and this vaccine will be “helpful in achieving that goal.”
Macaya Douoguih, MD, of J&J’s Janssen unit where the vaccine was developed, discussed the potential advantages of a one-dose vaccine, citing the company’s experience with the Ebola outbreak, where they developed a vaccine with the same Ad.26 adenovirus vector platform.
“For an outbreak setting, a single dose has a tremendous advantage in terms of being able to rapidly roll out mass vaccination” without the complexity of following up for a second dose, she said.
Douoguih addressed the company’s planned two-dose study, which drew the attention of FDA advisory committee members on Friday, and said that while the two-dose regimen could be “more immunogenic and lead to durable efficacy,” she thought there was room for both strategies.
If the COVID-19 vaccination becomes more “routine” in the future, Douoguih envisioned “the primary series for certain age groups could be a two-dose series instead of one,” but a single dose would still be optimal in an “outbreak setting.”
With the goal of vaccinating as many people as possible, Douoguih said the company had enrolled adolescents in a study starting next week, in the hopes of getting data as quickly as possible among ages 16-17 “so we could submit that data for review and maybe add to the EUA,” she said.
When reviewing data about evidence for a recommendation, CDC researchers discussed preliminary data about asymptomatic infection, which assessed seroconversion between days 29 and 71 and was based on detection of N-binding antibody among asymptomatic people.
Those data showed vaccine efficacy against seroconversion was 74% (95% CI 48%-87%), but both CDC and ACIP members urged caution. CDC researchers gave the data a “low certainty of evidence,” given the data was only preliminary.
“Our level of confidence in asymptomatic infection is tempered by low numbers and that is important for us to remember,” said ACIP committee member Sarah Long, MD, of Drexel University College of Medicine in Philadelphia. “I appreciate the workgroup concluding the confidence is not that high.”
Washington Editor Joyce Frieden contributed to this report.