Respiratory syncytial virus (RSV) is the most common respiratory pathogen in infants and children under 2 years of age with 64 million infections per year. The goal of our research is to develop a vaccine against RSV, using novel adjuvant formulations that are expected to induce high-affinity neutralizing antibodies and cell-mediated immune responses to RSV, leading to protection from RSV infection. Since an inappropriate, unbalanced immune response may result in immunopathology as opposed to protection, it is critical that a RSV vaccine induces the appropriate, protective, immune response. If a mathematical model could be designed to correlate the quality and magnitude of RSV vaccine-induced immune responses to protective immunity as opposed to immunopathology, this then might be used to predict the efficacy, and most importantly safety, of RSV vaccine candidates and possibly reduce the number of trials and animal models needed prior to clinical studies. Such a model would have the potential to more rapidly move the development of a RSV vaccine forward.