Abstract: In this talk, I will discuss the effective worldsheet theory of Abrikosov–Nielsen–Olesen (ANO) superconducting vortex strings in the Abelian Higgs model. After reviewing the effective string theory and the construction of the ANO vortex background, I will present a comprehensive study of the fluctuation spectrum around the ANO string. Specifically, I will classify the excitation spectra on the worldsheet, which contain both bound and scattering states, including the worldsheet axion, dilaton, and a variety of additional modes beyond the translational Goldstone modes. I will then show how these massive modes, after being integrated out, contribute to non-universal higher-curvature corrections to the Nambu–Goto action and determine two Wilson coefficients. I will conclude by comparing these results to features of confining strings in Yang–Mills theory. Based on work to appear with Thomas Dumitrescu and Amey Gaikwad.