Pre-clinical
vaccines not yet in human trials
Phase 1
vaccines in small-scale safety trials
Phase 2
vaccines in expanded safety trials
Phase 3
vaccines in large-scale efficacy trials
The Pfizer/BioNTech vaccine was reported to prevent 90% of infections in trials, much better than experts had expected
Pre-clinical
vaccines not yet
in human trials
Phase 1
vaccines in small-
scale safety trials
Phase 2
vaccines in expanded
safety trials
Phase 3
vaccines in large-
scale efficacy trials
The Pfizer/BioNTech vaccine was reported to prevent 90% of infections in trials, much better than experts had expected
Pre-clinical
vaccines not yet in
human trials
Phase 1
vaccines in small-
scale safety trials
Phase 2
vaccines in expanded
safety trials
Phase 3
vaccines in large-
scale efficacy trials
The Pfizer/BioNTech vaccine was reported to prevent 90% of infections in trials, much better than experts had expected