FDA's Vaccines and Related Biological Products Advisory Committee (VRBPAC) on Friday voted 19-0 to recommend booster doses of Johnson & Johnson's (J&J) Covid-19 vaccine for all recipients ages 18 and older.

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Advisory panel votes to recommend J&J booster shots

The panel voted to recommend booster doses to all J&J recipients ages 18 or older at least two months after the initial dose.

According to real-world evidence, a single dose of J&J's vaccine significantly reduces Covid-19 infections and hospitalizations, but it is less effective than Moderna's and Pfizer-BioNTech's vaccines—both of which are provided in two-dose regiments.

At the meeting, J&J said while protection from a single dose of its vaccine remains durable over time, two doses increases that protection to 94% against symptomatic infection and 100% against severe disease.

Although several panel members criticized the limited data presented by J&J and a lack of independent verification from FDA, Arnold Monto, a professor of epidemiology at the University of Michigan School of Public Health and VRBPAC's acting chair, said, "There is a public health imperative here because what we're seeing is that this is a group with overall lower efficacy than we have seen with the mRNA vaccines. So, there is some urgency there to do something."

Several panel members suggested that, given the lower effectiveness of a single dose compared to mRNA vaccines, the J&J vaccine should have initially been given via a two-dose regimen.

"I think, frankly, this was always a two-dose vaccine," said Paul Offit, director of the Vaccine Education Center at the Children's Hospital of Philadelphia. "It's hard to recommend this as a one-dose vaccine."

Next, FDA will consider granting emergency use authorization for booster doses of J&J's vaccine based on the panel's recommendation. Although the agency typically follows VRBPAC's recommendation, it is not required to.

J&J recipients will likely be able to mix and match vaccine boosters, Fauci says

During VRBPAC's meeting, panel members also reviewed a study from NIH that examined the possibility of mixing and matching booster doses of different vaccines. Although no vote was taken at the time, some members expressed support for allowing people to switch between vaccine brands for booster doses.

"From a public health perspective, there's a clear need in some situations for individuals to receive a different vaccine," said Amanda Cohn, CMO of CDC's National Center for Immunization and Respiratory Diseases.

Ofer Levy, an infectious diseases physician at Boston's Children Hospital, said FDA should act on mixing and matching booster doses because some people are already seeking boosters on their own.

"In the real world, all these kinds of combinations or extra boosters are already happening," Levy said. "We can't hide from it, and I do think we need to give guidance to the public."

Separately, Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said he believes J&J recipients will have flexibility in mixing and matching booster doses based on their individual situations.

In particular, he noted data that suggests mRNA vaccines produce a stronger antibody response in J&J recipients when given as a booster dose compared with a second J&J dose.

"If you look at the data from J&J that they presented to the FDA, when they use their own product as a boost, it's based on clinical data from a clinical trial," Fauci said. "The mix and match … shows that when you boost Moderna or Pfizer against the original J&J, you get a much higher antibody level."

He added, "I believe there's going to be a degree of flexibility of what a person who got the J&J originally can do, either with J&J or with the mix-and-match from other products." (Weise/Weintraub, USA Today, 10/15; Hensley, NPR, 10/15; Herper/Branswell, STAT News, 10/15; Reed, Axios, 10/15; LaFraniere et al., New York Times, 10/15; Beals, The Hill, 10/17; Saric, Axios, 10/17)