The Food and Drug Administration’s independent advisory committee meets Thursday to decide whether to recommend a booster shot of Moderna’s Covid-19 vaccine to the general public, a decision that comes amid questions over the need for booster shots of this vaccine.
The panel, which is made up of outside experts who advise the FDA’s decisions on vaccines, is set to vote later on Thursday on whether booster shots are safe and effective for a specific subset of Americans.
After the same panel ruled against Pfizer-BioNTech’s application to give boosters to all Americans, Moderna is seeking to reach the audience Pfizer was approved for: People 65 and older, those between 18 and 64 at high risk for severe Covid-19 and those whose occupations put them at increased risk for the disease.
The company is also only seeking authorization for a 50-microgram dose, which is about half the strength of the original mRNA vaccine given in two shots a few weeks apart.
Voting will follow presentations from Moderna executives, scientists with the Food and Drug Administration and Israeli health officials, as well as members of the public, who will be given the chance to voice their opinions.
While the FDA is not required to adhere to the decision of the Vaccines and Related Biological Products Advisory Committee (VRBPAC), it often does and has for critical decisions throughout the Covid-9 pandemic.
The FDA will be expected to issue its decision on Moderna booster shots within a few days of this panel’s vote before an advisory committee for the Centers for Disease Control and Prevention (CDC) meets to discuss next week who should get the shots and when.
What To Watch For
A two-day event, the FDA advisors will meet again on Friday to debate Johnson & Johnson’s booster shot. The J&J vaccine only required one shot, so experts will be considering the need for a second dose, which many have long argued to be necessary given its lower efficacy.
The FDA advisors are expected to be more skeptical of recommending boosters of Moderna’s Covid-19 vaccine because of the lack of evidence showing a decline in efficacy against severe disease. A recent CDC study found that while Pfizer’s vaccine fell from 91% to 77% effective at preventing hospitalization from the virus over a four-month period, the Moderna vaccine showed no decline during this time. However, Moderna released the results of a large clinical trial last month which estimated the waning immunity of its vaccine would lead to 600,000 additional cases of Covid-19, including some severe cases (it did not identify how many). Moderna appears to be basing its case on preventing an increase in breakthrough infections, but FDA staff are already doubting whether this is enough to justify an additional dose. Scientists from inside the agency said Tuesday that Moderna had not met all the agency’s criteria to support use of booster doses as the difference in antibody levels before and after the shot was not enough.
“Some real world effectiveness studies have suggested declining efficacy of Moderna COVID-19 Vaccine over time against symptomatic infection or against the Delta variant, while others have not,” the FDA scientists wrote in an assessment ahead of the meeting. “However, overall, data indicate that currently US-licensed or authorized COVID-19 vaccines still afford protection against severe COVID-19 disease and death in the United States.”
“Moderna vs. Pfizer: Both Knockouts, but One Seems to Have the Edge” (The New York Times)
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