Table 1.

Main characteristics of the four COVID-19 vaccines approved in Europe as of July 28, 2021

Developer	Commercial name	Type	Number of doses	Dosage interval
Pfizer–BioNTech	Comirnaty	mRNA-based	2	3–12 weeks
Moderna	COVID-19 Vaccine Moderna	mRNA-based	2	4 weeks
AstraZeneca	Vaxzevria	Adenovirus vector-based	2	4–12 weeks
Johnson and Johnson - Janssen Pharmaceuticals	COVID-19 Vaccine Janssen	Adenovirus vector-based	1	–