The vaccine development pipeline has been accelerated for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including overlapping of clinical trial phases and at-risk production of vaccines still in clinical trials. Despite this, it is vital that factors such as age, sex, and pregnancy be considered throughout the development process. Vaccine platforms are designed in early exploratory studies, and for SARS-CoV-2, much of this discovery was taken from platforms designed for SARS coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV). These platforms are then tested in preclinical animal models for characterization including safety, toxicity, and immunogenicity. Diverse animal models including rodents and nonhuman primates of both sexes, as well as aged and pregnant animals, can help to elucidate how diverse populations will react to vaccine candidates. After preclinical studies, an investigational new drug (IND) application is submitted, and once approved, the vaccine candidate can be tested in humans in clinical trials. During the enrollment process, there should be sex-balanced enrollment as well as enrollment of older adults and pregnant women if the animal data support safety and efficacy in these groups. With the data from these trials, a biologics license application (BLA) is submitted to regulatory agencies for approval and/or EUA. When SARS-CoV-2 vaccines are widely distributed, it is vital that pregnant women have access to the vaccine and that there are empirical data supporting its safety and efficacy in pregnant women.