Quote:
The use of mRNA has several beneficial features over subunit, killed and live attenuated virus, as well as DNA-based vaccines.
First, safety: as mRNA is a non-infectious, non-integrating platform, there is no potential risk of infection or insertional mutagenesis. Additionally, mRNA is degraded by normal cellular processes, and its in vivo half-life can be regulated through the use of various modifications and delivery methods9,10,11,12. The inherent immunogenicity of the mRNA can be down-modulated to further increase the safety profile9,12,13.
Second, efficacy: various modifications make mRNA more stable and highly translatable9,12,13. Efficient in vivo delivery can be achieved by formulating mRNA into carrier molecules, allowing rapid uptake and expression in the cytoplasm (reviewed in Refs 10,11). mRNA is the minimal genetic vector; therefore, anti-vector immunity is avoided, and mRNA vaccines can be administered repeatedly.
Third, production: mRNA vaccines have the potential for rapid, inexpensive and scalable manufacturing, mainly owing to the high yields of in vitro transcription reactions.
And thankfully MERS onset of symptoms was fast. So isolating those that were symptomatic until they got better or died contained it. That's why the first reactions to COVID was a 2 week lockdown. If MERS had the 3-5 day asymptomatic infectious period, it would be the new Black Death or The Stand.