Research on covid-19 vaccines adapted to the omicron xbb.1.5 variant is being conducted, with studies examining the immunogenicity, safety, and efficacy of various vaccine formulations. The vaccines being tested include monovalent and bivalent options, as well as trivalent recombinant protein vaccines, with some studies reporting broadly neutralizing and cellular immune responses. The results of these studies are being published in various scientific journals, including nature and the lancet.