Health: immunizations; administration of gene-based vaccines; prohibit. Amends secs. 9201 & 16221 of 1978 PA 368 (MCL 333.9201 & 333.16221) & adds sec. 9228.

HB 4778 prohibits the administration of gene-based vaccines (including mRNA, modified mRNA, self-amplifying mRNA, and DNA vaccines) by any person or governmental entity in Michigan. The bill amends the Public Health Code to add Section 9228, explicitly banning the ordering or giving of these specific vaccines, while clarifying that "immunizing agents" (like traditional vaccines) remain unaffected. This directly affects healthcare providers, clinics, hospitals, and public health entities that administer vaccines, requiring them to stop using gene-based vaccines. The law focuses solely on gene-based vaccine administration and does not change requirements for other types of immunizations.