Table 2.

Characteristics of COVID-19 RNA vaccines.

Vaccine	Developer	Route of administration/ dose	Clinical stage	Subunit and structure	Adjuvant	Efficacy	Side effects	Reference
mRNA-1273 vaccine	ModernaTX, Inc.	IM/2	Phase 4	LNP	No adjuvant	100% efficacy against B.1.1.7; 95.7% efficacy against B.1.35 in Qatar and 94.1%in United States	Systemic adverse events were more common after the second vaccination. Serious adverse events were rare.	Baden et al., 2021; Chemaitelly et al., 2021; Corbett et al., 2021
mRNA-1273.351 vaccine	ModernaTX, Inc.	IM/2	Phase 2	LNP	No adjuvant	NR	NR	Baden et al., 2021
BNT162b2 (Comirnaty) vaccine	Pfizer-BioNTech	IM/2	Phase 4	LNP	No adjuvant	95% (based on phase 2/3)	Mild-to-moderate pain at the injection site within 7 days after injection, injection-site redness or swelling, fever, fatigue, and headache	Sahin et al., 2021
CVnCoV vaccine	CureVac N.V.	IM/2	Phase 3	LNP	No adjuvant	48.2% (phase 2b/3)	Injection-site pain, fatigue, headache, None of the fatal serious adverse events reported	Hoffmann et al., 2021; Kremsner et al., 2021
ARCoV vaccine	AMS, Walvax Biotechnology and Suzhou Abogen Bio-sciences	IM/2	Phase 3	LNP	No adjuvant	NR	NR	ClinicalTrials.gov, 2021a
mRNA-1273.211 vaccine	ModernaTX, Inc.	IM/2	Phase 2	LNP	No adjuvant	NR	NR	Clinicaltrials.gov, 2022b
ARCT-154 mRNA vaccine	Arcturus Therapeutic	IM/2	Phase1/2/ 3	self-amplifying mRNA	No adjuvant	NR	NR	Vietnam News Agency, n.d.; Clinical Trials Arena, 2021; ClinicalTrials.gov, 2022c

NR: Not Reported. IM: Intramuscular. IN: Intranasal. LNP: lipid nanoparticle.