Pfizer (NYSE:PFE) and Moderna (NASDAQ:MRNA) announced clinical trial data to reaffirm the effectiveness and safety of their messenger RNA-based COVID shots on Tuesday after President Donald Trump called on the vaccine makers to justify their success earlier this month.
New York-based Pfizer (NYSE:PFE) highlighted Phase 3 data suggesting that its updated COVID shot developed with BioNTech (NASDAQ:BNTX) for the 2025-2026 respiratory vaccine season has caused at least a fourfold increase in antibodies against the LP.8.1 variant, which it is designed to target.
“COVID-19 vaccines, especially the mRNA COVID-19 vaccines, have been instrumental in preventing millions of deaths and reducing severe illness worldwide during and after the pandemic,” remarked Chief Scientific Officer Chris Boshoff.
Meanwhile, Moderna (NASDAQ:MRNA) added that its Spikevax vaccine adjusted for LP.8.1 caused, on average, an over eightfold increase in neutralizing antibodies against the variant in an ongoing Phase 4 trial.
The trial, designed to evaluate the safety, tolerability, and immunogenicity of the updated shot, enrolled adults aged 65 years and older and those aged 12–64 with one or more underlying health conditions that increase their susceptibility to COVID.
Last month, the FDA authorized both shots for all adults aged 65 and older and for at-risk individuals aged 6 months to 64 years, based on preclinical data.
However, days after the approval, Trump wrote on social media that the question over the success of their COVID drugs has “ripped apart” the U.S. CDC. “They show me GREAT numbers and results, but they don’t seem to be showing them to many others. I want them to show them NOW, to the CDC and the public, and clear up this MESS, one way or the other!!!” he wrote during the Labor Day weekend.
The announcements also precede this week’s meeting of the CDC’s vaccine advisory panel, in which independent experts of the agency are expected to discuss key recommendations such as eligibility requirements for the fall COVID-19 booster shots.