A novel lipid nanoparticle–encapsulated nucleoside-modified mRNA (mRNA-LNP) vaccine may offer protective effects against the Lyme disease–causing Borrelia burgdorferi bacteria, according to a recent study published by Pine et al in Molecular Therapy. In the study, researchers developed an outer surface protein A–encoding mRNA-LNP vaccine and compared its efficacy to that of an alum-adjuvanted outer surface protein A subunit vaccine in mouse models. After a single immunization, the novel mRNA-LNP vaccine provided superior humoral and cell-mediated immune responses and successfully prevented Lyme disease. The researchers concluded that these types of vaccines may be utilized to protect against Lyme disease–causing bacterial infections and the subsequent development of posttreatment Lyme disease syndrome.