Moderna's booster plan comes into focus with pre-print studies in immunocompromised populations, Delta breakthroughs
Moderna submitted initial data to the FDA for its Covid-19 vaccine booster plan earlier this week, and that plan is sharpening into view following several published pre-prints over the last few weeks.
Studies outlining the Moderna vaccine’s effectiveness in different immunocompromised populations, as well as examining the shots’ ability to prevent breakthrough infections, have come to light recently. And most, if not all, of the pre-prints show Moderna’s shot netting higher rates at preventing Covid-19 than the jab from Pfizer and BioNTech.
Moderna pointed to the studies in a press briefing Friday morning as likely to be included in booster data submissions, touting its results in head-to-head comparisons with Pfizer.
In a pre-print published last month looking at mRNA vaccine effectiveness in more than 1,500 individuals on maintenance dialysis, researchers observed a 96% serologic response among those who received two doses of the Moderna shot. That rate compared to an 87% rate in patients who got the Pfizer/BioNTech shot and 37% in those who received the J&J vaccine.
Of the 1,528 people in the study, 766 received Moderna shots. Another 437 patients received the Pfizer/BioNTech shot, while 325 got the J&J jab.
Another pre-print posted in August looked at real-world data from vaccine recipients in Qatar. This study, looking specifically at breakthrough infections due to the Delta variant, found the Moderna shot had much higher rates at preventing symptomatic infection than the Pfizer/BioNTech vaccine.
As of the end of the study on July 21, researchers had observed a 79% effectiveness rate 14 days after one Moderna shot and a 84.8% rate 14 days after the second shot. Those figures — observing any symptomatic breakthrough case — contrasted with the Pfizer/BioNTech vaccine, which saw rates of 64.2% and 53.5%, respectively.
Additionally, Moderna recorded 100% effectiveness at preventing severe disease or hospitalization due to Delta, compared to 89.7% for Pfizer/BioNTech.
As with any pre-print, none of the data have been peer reviewed.
Moderna announced Wednesday it had submitted booster shot plans for a 50 µg dose, lower than the 100 µg dose currently authorized under emergency use. Earlier this week, the company said a 50 Xg booster resulted in antibody titer levels “significantly above the Phase 3 benchmark.”
The booster submission came just a week after the biotech wrapped up its BLA for the original, two-dose regimen. Pfizer and BioNTech received full approval for their Covid-19 vaccine on Aug. 23, and a booster shot adcomm is planned for Sept. 17.
The new adcomm comes amid concerns that President Joe Biden’s administration had meddled with the regulatory process by unveiling a nationwide booster campaign ahead of any FDA reviews. The perceived overreach was what, ultimately, contributed to the sudden departures of two top officials who have been leading the agency’s vaccine review for years, a former senior FDA leader said.