This document discusses two types of mRNA vaccines: non-replicating mRNA and self-amplifying mRNA. Self-amplifying mRNA contains non-structural genes that allow for self-amplification of the mRNA within cells. It works by inserting the nucleic acid sequence encoding the antigen directly into single-stranded RNA viruses like Semliki Forest virus or yellow fever virus.

1.  Non-replicating mRNA
 Self-amplifying mRNA
Non-structural genes for
self-amplification.
Virus-derived self-amplifying mRNA is
to insert the nucleic acid sequence
encoding antigen directly into single-
stranded RNA virus, such as Semliki
forest virus, yellow fever virus, etc.
5’-G P P P UTR nsP4
ORF UTR AAAAAA(140-150)-3’
nsP3 nsP2 nsP1
SP
CAP 5‘Untranslated Region
Insert Fragment
CAP 3‘ Untranslated Region Poly A Tail
Types of mRNA vaccine