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Both regulatory and non-regulatory efforts may be needed to help immunocompromised patients receive additional doses of COVID-19 vaccine, CDC staff said during a meeting of the Advisory Committee on Immunization Practices (ACIP) on Thursday.

They confirmed that the FDA can permit additional doses of COVID-19 vaccine for this population, either via an amendment to the emergency use authorization (EUA) or off-label use if a vaccine was fully approved.

However, FDA liaison Doran Fink, MD, PhD, noted that the agency has yet to receive the data that would support "any regulatory mechanisms or actions."

"FDA is actively exploring all regulatory options to providing additional doses of authorized vaccines in cases where the benefits would outweigh the risks," he said.

ACIP executive secretary Amanda Cohn, MD, of the CDC, alluded to how the agency is looking for ways to "provide access" to additional vaccine doses for these patients, in light of any regulatory issues.

Indeed, ACIP member Camille Kotton, MD, of Massachusetts General Hospital in Boston, who has cared for immunocompromised patients for over 20 years, expressed frustration that she cannot recommend additional doses of vaccine. She also warned the committee that her patients are "taking matters into their own hands" and "proceeding with additional vaccine doses as they see fit."

During the public comment session, several immunocompromised patients spoke about how they have been forced to shut themselves out of society for their own safety, despite being fully vaccinated. One patient even said he was considering going to a vaccination site and lying about his vaccination history to get a third dose.

ACIP member Lynn Bahta, RN, of the Minnesota Department of Health, added that a few health systems in her state were already developing policies for vaccinating immunocompromised patients, ahead of any authorization.

"The issue is running away from us," she said.

CDC staff reviewed data that indicated that among those with no detectable antibody response to an initial 2-dose mRNA vaccine series, 33% to 50% developed a response to a third dose.

Members had varying opinions on what ACIP should do following any future regulatory action allowing a third dose in this population, with some members wanting shared clinical decision making and others preferring an outright recommendation.

They also agreed that it would be important to monitor safety, although in a study of 99 patients, there were no serious adverse events after a third dose in organ transplant recipients and no rejection episodes occurred.

J&J Vaccine Benefits Outweigh Guillain-Barré Safety Signal

On July 12, FDA added a warning to the Johnson & Johnson vaccine indicating an increased risk of Guillain-Barré syndrome (GBS) within 42 days after vaccination. Agency staff shared more details about preliminary cases of GBS reported to the Vaccine Adverse Event Reporting System (VAERS) as of June 30. However, they emphasized that the cases had not been adjudicated using the Brighton case definition.

Among the 100 cases, median age was 57, and 61% were men. Notably, 83% of cases occurred among adults ages 18-64. Median time to onset was 13 days, and 98% of cases were in the 42-day risk window.

There were 95 severe cases, 10 patients who were intubated or required ventilation, and one death in a 57-year-old man with past medical history of heart failure, stroke, hypertension, and diabetes. He was hospitalized for 11 days, on a ventilator for 6 days, and died 25 days following vaccination.

The crude GBS reporting rate for Johnson & Johnson's vaccine was substantially higher than for the mRNA vaccines (8.1 per million doses vs 1.1 per million, respectively, compared with 1.6 cases of GBS per million expected).

Still, ACIP members agreed that the benefits of an authorized 1-dose vaccine outweighed the risks, especially in light of the rising Delta variant. Alternate vaccines should be available so people could make the choice themselves, they said, and any rare adverse events should be stated upfront.

ACIP chair José Romero, MD, gave his perspective from being in the middle of a Delta surge in Arkansas.

"Having access to a single-dose vaccine is very important to move us out of this situation," he said, noting there are "individuals who will not come back for a second dose" of mRNA vaccine.

While myocarditis in teenagers was brought up by several committee members, CDC staff said they expect to discuss the issue at a later meeting when more data are made available for adolescents ages 12 to 18.

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