Is ipsilateral administration of COVID-19 vaccine boosters the optimal approach?

Competing Interests: Declaration of interests M.S. has received grant support from Astellas and Biotest to the organization Saarland University outside the submitted work, and honoraria and travel support for lectures from Biotest, MSD, Takeda, Qiagen and Novartis, and for advisory boards from Moderna, Biotest, MSD and Takeda outside of the submitted work. T.S. has received travel support from Biotest for attending a meeting outside the submitted work. S.L.B. has participated in advisory boards with Shionogi and Pfizer outside the submitted work. B.C.G. has received honoraria for lectures from BioNTech, Moderna, Sanofi, CSL Seqirus, and GSK, and travel support from Pierre Fabre outside of the submitted work. All other authors of this manuscript have no conflicts of interest to disclose.