What is self-amplifying mRNA technology? Self-amplifying mRNA (SAM) technology is a relatively novel approach in vaccinology. It consists of an engineered replication-deficient alphavirus genome encoding an RNA-dependent RNA polymerase and the gene of the target antigen. The benefit that SAM technology holds over conventional vaccinology is its potential for the rapid development and large-scale production of a vaccine in the event of an unpredictable epidemic outbreak.