Moderna's mRNA Flu Vaccine Approved By FDA. The FDA Just Approved a Biological Weapon Aimed at the Elderly — and They Call It a Flu Shot. The Silent Shot: Uncovering the mRNA Flu Vaccine's Hidden Toll on the Elderly. When regulators knew more than they told: The untold story of mRNA vaccine biodistribution. Breaking: Moderna's mRNA Flu Vaccine Gets Unanimous Thumbs-Up Despite Risks, Low Efficacy.