J&J COVID-19 Vaccine Wins Unanimous Backing of FDA Panel

Kerry Dooley Young

February 26, 2021

Editor's note: Find the latest COVID-19 news and guidance in Medscape's Coronavirus Resource Center.

An FDA advisory panel lent their support today to a rapid clearance for Janssen/Johnson & Johnson's COVID-19 vaccine.

The Food and Drug Administration (FDA) is expected to quickly provide an emergency use authorization (EUA) for the vaccine following the recommendation by the panel. The FDA's Vaccines and Related Biological Products Advisory Committee voted 22-0 on this question: Based on the totality of scientific evidence available, do the benefits of the Johnson & Johnson COVID-19 Vaccine outweigh its risks for use in individuals 18 years of age and older?

The Johnson & Johnson vaccine is expected to offer more convenient dosing and be easier to distribute than the two rival products already available in the United States. Janssen's vaccine is intended to be given in a single dose. In December, the FDA granted EUAs for the Pfizer/BioNTech and Moderna COVID-19 vaccines, which are each two-dose regimens.

Johnson & Johnson's vaccine can be stored for at least 3 months at normal refrigerator temperatures of 2°C to 8°C (36°F to 46°F). Its shipping and storage fits into the existing medical supply infrastructure, the company said in its briefing materials for the FDA advisory committee meeting. In contrast, Pfizer's vaccine is stored in ultracold freezers at temperatures between -80°C and -60°C (-112°F and -76°F), according to the Centers for Disease Control and Prevention. Moderna's vaccine may be stored in a freezer between -25°C and -15°C (-13°F and 5°F).

But FDA advisers focused more in their deliberations on concerns about Janssen's vaccine, including emerging reports of allergic reactions.

The advisers also discussed how patients might respond to the widely reported gap between Johnson & Johnson's topline efficacy rates compared with rivals. The company's initial unveiling last month of key results for its vaccine caused an initial wave of disappointment, with its overall efficacy against moderate-to-severe COVID-19 28 days postvaccination first reported at about 66% globally. By contrast, results for the Pfizer and Moderna vaccines suggest they have efficacy rates of 95% and 94%.

But in concluding, the advisers spoke of the Janssen vaccine as a much-needed tool to address the COVID-19 pandemic. The death toll in the United States attributed to the virus has reached 501,414, according to the World Health Organization.

"Despite the concerns that were raised during the discussion. I think what we have to keep in mind is that we're still in the midst of this deadly pandemic," said FDA adviser Archana Chatterjee, MD, PhD, from Rosalind Franklin University. "There is a shortage of vaccines that are currently authorized, and I think authorization of this vaccine will help meet the needs at the moment."

The FDA is not bound to accept the recommendations of its advisers, but it often does so.

Anaphylaxis Case

FDA advisers raised only a few questions for Johnson & Johnson and FDA staff ahead of their vote. The committee's deliberations were less contentious and heated than had been during its December reviews of the Pfizer and Moderna vaccines. In those meetings, the panel voted 17-4, with one abstention, in favor of Pfizer's vaccine and  20-0, with one abstention, on the Moderna vaccine.

"We are very comfortable now with the procedure, as well as the vaccines," said Arnold Monto, MD, after the Friday vote on the Janssen vaccine. Monto, from the University of Michigan School of Public Health in Ann Arbor, has served as the chairman of the FDA panel through its review of all three COVID-19 vaccines.

Among the issues noted in today's deliberations was the emergence of a concern about anaphylaxis with the vaccine.

This serious allergic reaction has been seen in people who have taken the Pfizer and Moderna vaccines. Before this week, though, there had not been reports of anaphylaxis with the Johnson & Johnson vaccine, said Macaya Douoguih, MD, MPH, head of clinical development and medical affairs for Janssen/ Johnson & Johnson's vaccines division.

However, on February 24, Johnson & Johnson received preliminary reports about two cases of severe allergic reaction from an open-label study in South Africa, with one of these being anaphylaxis, Douoguih said. The company will continue to closely monitor for these events as outlined in their pharmacovigilance plan, Douoguih said.

Federal health officials have sought to make clinicians aware of the rare risk for anaphylaxis with COVID vaccines, while reminding the public that this reaction can be managed.

The FDA had Tom Shimabukuro, MD, MPH, MBA, from the CDC, give an update on postmarketing surveillance for the Pfizer and Moderna vaccines as part of the review of the Johnson & Johnson application. Shimabukuro and CDC colleagues published a report in JAMA on February 14 that looked at an anaphylaxis case reported connected with COVID vaccines between December 14, 2020, and January 18, 2021.

The CDC identified 66 case reports received that met Brighton Collaboration case definition criteria for anaphylaxis (levels 1, 2, or 3): 47 following Pfizer/BioNTech vaccine, for a reporting rate of 4.7 cases/million doses administered, and 19 following Moderna vaccine, for a reporting rate of 2.5 cases/million doses administered, Shimabukuro and CDC colleagues wrote.

The CDC has published materials to help clinicians prepare for the possibility of this rare event, Shimabukuro told the FDA advisers.

"The take-home message here is that these are rare events and anaphylaxis, although clinically serious, is treatable," Shimabukuro said.

At the conclusion of the meeting, FDA panelist Patrick Moore, MD, MPH, from the University of Pittsburgh in Pennsylvania, stressed the need to convey to the public that the COVID vaccines appear so far to be safe. Many people earlier had doubts about how the FDA could both safely and quickly review the applications for EUAs for these products.

"As of February 26, things are looking good. That could change tomorrow," Moore said. But "this whole EUA process does seem to have worked, despite my own personal concerns about it."

No Second-Class Vaccines

The Johnson & Johnson  vaccine, known as Ad26.COV2.S, is composed of a recombinant, replication-incompetent human adenovirus type 26 (Ad26) vector. It's intended to encode a stabilized form of SARS-CoV-2 spike (S) protein. The Pfizer and Moderna vaccines use a different mechanism. They rely on mRNA.

The FDA advisers also discussed how patients might respond to the widely reported gap between Janssen's topline efficacy rates compared with rivals. They urged against people parsing study details too finely and seeking to pick and choose their shots.

"It's important that people do not think that one vaccine is better than another," said FDA adviser H. Cody Meissner, MD, from Tufts University School of Medicine in Boston, Massachusetts.

Monto agreed, noting that many people in the United States are still waiting for their turn to get COVID vaccines because of the limited early supply.

Trying to game the system to get one vaccine instead of another would not be wise. "In this environment, whatever you can get, get," Monto said.

During an open public hearing, Sarah Christopherson, policy advocacy director of the National Women's Health Network, said that press reports are fueling a damaging impression in the public that there are "first and second-class" vaccines.

"That has the potential to exacerbate existing mistrust” in vaccines, she said. "Public health authorities must address these perceptions head on."

She urged against attempts to compare the Janssen vaccine to others, noting the potential effects of emerging variants of the virus.

"It's difficult to make an apples-to-apples comparison between vaccines," she said.

Johnson & Johnson's efficacy results, which are lower than those of the mRNA vaccines, may be a reflection of the ways in which SARS-Co-V-2 is mutating and thus becoming more of a threat, according to the company. A key study of the new vaccine, involving about 44,000 people, coincided with the emergence of new SARS-CoV-2 variants, which were emerging in some of the countries where the pivotal COV3001 study was being conducted, the company said.

At least 14 days after vaccination, the Johnson & Johnson COVID vaccine efficacy (95% confidence interval) was 72.0% (58.2, 81.7) in the United States, 68.1% (48.8, 80.7) in Brazil, and 64.0% (41.2, 78.7) in South Africa.

Weakened Standards?

Several researchers called on the FDA to maintain a critical attitude when assessing Johnson & Johnson's application for the EUA, warning of a potential for a permanent erosion of agency rules due to hasty action on COVID vaccines.

They raised concerns about the FDA demanding too little in terms of follow-up studies on COVID vaccines and with persisting murkiness resulting in attempts to determine how well these treatments work beyond the initial study period.

"I worry about FDA lowering its approval standards," said Peter Doshi, PhD, from The BMJ and a faculty member at the University of Maryland School of Medicine in Baltimore, during an open public hearing at the meeting.

"There's a real urgency to stand back right now and look at the forest here, as well as the trees, and I urge the committee to consider the effects FDA decisions may have on the entire regulatory approval process," Doshi said.

Doshi asked why Johnson & Johnson did not seek a standard full approval — a biologics license application (BLA) — instead of aiming for the lower bar of an EUA. The FDA already has allowed wide distribution of the Pfizer/BioNTech and Moderna vaccines through EUAs. That removes the sense of urgency that FDA faced last year in his view.

The FDA's June 2020 guidance on the development of COVID vaccines had asked drug makers to plan on following participants in COVID vaccine trials for "ideally at least one to two years." Yet people who got placebo in Moderna and Pfizer trials already are being vaccinated, Doshi said. And Johnson & Johnson said in its presentation to the FDA that if the Ad26.COV2.S vaccine were granted an EUA, the COV3001 study design would be amended to "facilitate cross-over of placebo participants in all participating countries to receive one dose of active study vaccine as fast as operationally feasible."

"I'm nervous about the prospect of there never being a COVID vaccine that meets the FDA's approval standard" for a BLA instead of the more limited EUA, Doshi said.

Diana Zuckerman, PhD, president of the nonprofit National Center for Health Research, noted that the FDA's subsequent guidance tailored for EUAs for COVID vaccines "drastically shortened" the follow-up time to a median of 2 months. Zuckerman said that a crossover design would be "a reasonable compromise, but only if the placebo group has at least 6 months of data." Zuckerman opened her remarks in the open public hearing by saying she had inherited Johnson & Johnson stock, so was speaking at the meeting against her own financial interest.

"As soon as a vaccine is authorized, we start losing the placebo group. If FDA lets that happen, that's a huge loss for public health and a huge loss of information about how we can all stay safe," Zuckerman said.

Kerry Dooley Young is a freelance journalist based in Washington, DC. She earlier covered health policy and the federal budget for Congressional Quarterly/CQ Roll Call and the pharmaceutical industry and the US Food and Drug Administration for Bloomberg. Follow her on Twitter at @kdooleyyoung.

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