U.S. health officials under Health Secretary Robert F. Kennedy Jr. have discussed sweeping changes to vaccine policy, including discouraging adjuvants used to boost shot effectiveness and splitting multivalent childhood vaccines into separate components, according to reporting in STAT. Manufacturers privately warned such moves could force reformulation, delay availability, and raise development costs dramatically. Industry sources told STAT that removing or rapidly reformulating vaccine ingredients could take a decade and cost upwards of $1 billion per vaccine. Companies cautioned that abrupt regulatory shifts could reduce access to established childhood immunizations and erode long-standing vaccination schedules. The reporting underscores acute regulatory uncertainty for vaccine developers: operational impacts range from CMC rework to clinical trials and supply-chain disruption, with potential public-health implications if coverage gaps emerge for diseases like measles, diphtheria, and polio.