Conflicts of Interest Balaji Narasimhan is a co-founder of Immuno Nano Med Inc., a start-up with business interests in the development of particle-based vaccines against infectious diseases. The other author declares no conflicts of interest. References 1, , , and , “Current Challenges in Vaccinology,” Frontiers in Immunology 11 (2020): 1181. 2 Policy (OIDP) O of ID and H, “Vaccine Types [Internet],” 2021, cited September 9, 2024, https://www.hhs.gov/immunization/basics/types/index.html.