A Food and Drug Administration review released Tuesday found that a booster shot of the modern coronavirus vaccine increased virus-fighting antibodies in people who received the standard two-dose regimen at least six months earlier.
Like Pfizer-BioNTech’s previous review of the booster’s evidence, the document struck a vague tone about whether the booster is now needed.
FDA reviewers noted that the half-dose booster shot of Moderna Vaccine is above antibody levels, the most easily measurable barometer of immunity. But he also pointed out that the usefulness of the booster would depend on factors that are unclear at this time – such as whether the safety of early vaccination has declined significantly.
“Overall, the data indicate that currently US-licensed or authorized COVID-19 vaccines still provide protection against serious COVID-19 illness and death in the United States,” the reviewers wrote.
The document was one of a series posted online ahead of a two-day meeting scheduled for Thursday and Friday, at which independent experts will advise the agency on questions related to boosters, including: additional shots of coronavirus vaccines developed by Moderna and Johnson Huh. johnson safe and effective? Does the data show that people can safely take a booster dose made by a different company than their original shot?
On Thursday, advisers are expected to consider data supporting Moderna’s third shot, which would be equal to half the dose of the original shot. The booster will be given at least six months after the initial vaccination.
On Friday, they are due to review evidence for a second shot of the Johnson & Johnson vaccine, six months after vaccination.
The advisories are also slated to consider data from a National Institutes of Health trial that tested mix-and-match boosters, which could simplify boosting.
Pfizer-BioEntech’s third shot of the vaccine was authorized by the FDA for certain people — including adults 65 years of age and older and those at risk of serious illness or exposed to the virus at work. Moderna is seeking authorization of its boosters for the same portion of the population “in the interest of public health,” the company said in a document filed with the FDA. Johnson & Johnson said its data shows a “favourable benefit-risk profile” for booster doses in people 18 years of age and older.
A key FDA official overseeing the vaccines indicated last week that his hope was to come up with a “harmonized approach” to boosters for people who had received any of the three vaccines available in the United States. Peter Marks, director of the Center for Biologics Evaluation and Research, said during a webinar that emerging data could support broader eligibility for a booster of all three shots — for anyone 18 years of age and older.
FDA documents reviewing modern data, such as those for Pfizer-BioNtech, note that authorized and approved vaccines provide protection against serious illness and death overall. It also said that major factors in the recent surge of coronavirus in the United States include the rise of the highly contagious delta variant, uneven use of public health measures to prevent transmission, and millions of people. Notably, it does not cite weakened immunity from vaccinated people as a major driver of the pandemic.
The review states, “Some real-world effectiveness studies have suggested a decline in the effectiveness of the modern COVID-19 vaccine against symptomatic infections or against the delta variant over time, while others have not. “
The Moderna findings in question include data on the third shot given to about 350 people. Half of the people in the study received a standard two-dose regimen to begin with, followed by a booster. Others got two doses to start, but at half the size of the usual regimen before getting a booster. The test measured virus-fighting antibody levels as a way of predicting that the booster would restore protection.
Moderna, in documents submitted to the FDA, cites a pre-print study of vaccinated individuals from Kaiser Permanente Southern California showing that the time immediately after vaccination ranged from 94% to 80% efficacy, five to six months after vaccination. There is a slight decline in vaccine efficacy with delta compared with . The vaccine’s efficacy was also lower in people over 65 years of age.
“We still see that people are very much protected from serious consequences, but overall there is a slight decrease against infection.” [vaccine efficacy] And this suggests that boosters potentially play a role as part of the vaccine strategy,” said Katia Brooksvoort, an assistant investigator at Kaiser Permanente Southern California who led the analysis.
A potential sticking point of harmonizing access to vaccine boosters by expanding eligibility to those 18 years and older: small but real risk of myocarditis – inflammation of the heart – following vaccination, particularly in younger men. No cases of this type of inflammation were found to be associated with the vaccine in the small trial.
“It is not currently known whether there will be an increased risk of myocarditis/pericarditis or other adverse reactions following a booster dose of Moderna COVID-19 Vaccine,” the reviewers wrote.
Boosters have become a controversial scientific issue, with many scientists and clinicians looking at the same data and arriving at different conclusions. When the Pfizer-BioNTech booster was considered a month ago, the FDA’s review was neutral as to whether the booster was widely needed in the general population. External advisors strongly rejected the idea of making them eligible for anyone aged 16 and older, the group that initially received the vaccines under the Vaccines’ December authorization.
Instead, FDA advisors recommended boosters of the Pfizer-BioNTech shot for people age 65 and older and those at risk for serious disease, a population expert broadly agreeing would benefit from a third shot. He also thought that people exposed to the virus on the job should be eligible. A few days later, the FDA authorized the vaccine for those segments of the population.
A Centers for Disease Control and Prevention advisory committee stopped short of recommending boosters for people exposed to the virus at work. But the agency’s director overturned that committee’s recommendation. CDC director Rochelle Valensky added a recommendation that people ages 18 to 64 at risk of exposure and transmission because of occupational or institutional settings can get a booster shot.
Booster’s case relied strongly on Israel’s evidence, and a representative of Israel’s health ministry would testify to experts again, presenting updated data. Israel used the Pfizer-BioNTech vaccine and, from late August, made the third shot available to people 12 and older.