Beta-Binomial Models for Immune Cell Frequencies and Power Calculations R package BBMBC version 1.0.1 Provides tools to model overdispersed immune cell frequencies using Beta-Binomial generalized linear models. Originally designed for memory B cells, the framework generalizes to evaluate rare cellular immune responses across vaccinology, immuno-oncology, and related fields. Includes method-of-moments dispersion estimation, likelihood ratio testing across experimental arms, and Monte Carlo simulation to calculate statistical power and Type I error rates. The methodologies are directly motivated by the analysis of immunology data in "Vaccination with mRNA-encoded membrane-anchored HIV envelope trimers elicited tier 2 neutralizing antibodies in a phase 1 clinical trial" (Parks et al. 2025) <doi:10.1126/scitranslmed.ady6831>. Software Depends: R (>= 4.1.0) Imports: doParallel, foreach, glmmTMB, parallel, stats, utils Suggests: testthat (>= 3.0.0) Andrew Shin <ashin2@uw.edu> Comprehensive R Archive Network (CRAN) Andrew Shin [aut, cre] MIT + file LICENSE (https://CRAN.R-project.org/package=BBMBC/LICENSE) 2026-10-31 application/tgz https://CRAN.R-project.org/package=BBMBC doi:10.32614/CRAN.package.BBMBC