Vaccine Choice

There have been no clinical trials directly comparing the PfizerBioNTech and AstraZeneca vaccines. In Phase III trials of the respective vaccines, efficacy against symptomatic disease for the Pfizer-BioNTech vaccine was higher than for the AstraZeneca vaccine.

Differences in study setting, study design, study population (age, ethnicity, social demographics, etc), and efficacy endpoints may account for some of the
observed differences.

Both vaccines give very high protection against severe disease, which is the primary aim of the first phase of the programme, and both vaccines have good safety profiles.