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PF-07302048 (BNT162 RNA-Based COVID-19 Vaccines)
Protocol C4591001

Number of Participants

Each group in Phase 1 will comprise 15 participants (12 receiving active vaccine and
3 receiving placebo). In this phase, 13 groups will be studied, corresponding to a total of
195 participants.

The vaccine candidate selected for Phase 2/3, BNT162b2 at a dose of 30 µg, will comprise
21,999 vaccine recipients. The 12- to 15-year stratum will comprise up to approximately
2000 participants (1000 vaccine recipients) enrolled at selected investigational sites. It is
intended that a minimum of 40% of participants will be in the >55-year stratum. An equal
number of participants will receive placebo, ie, randomized in a 1:1 ratio.

Intervention Groups and Duration

The study will evaluate a 2-dose (separated by 21 days) schedule of various different dose
levels of 2 investigational RNA vaccine candidates for active immunization against
COVID-19 in 3 age groups (Phase 1: 18 to 55 years of age, 65 to 85 years of age; Phase 2/3:
≥12 years of age [stratified as 12-15, 16-55, or >55 years of age]):

• BNT162b1 (BNT162 RNA-LNP vaccine utilizing modRNA and encoding the RBD):
10 µg, 20 µg, 30 µg, 100 µg

• BNT162b2 (BNT162 RNA-LNP vaccine utilizing modRNA and encoding the P2 S):
10 µg, 20 µg, 30 µg

The vaccine candidate selected for Phase 2/3 evaluation is BNT162b2 at a dose of 30 µg.

Participants are expected to participate for up to a maximum of approximately 26 months.
The duration of study follow-up may be shorter among participants enrolled in Phase 1
dosing arms that are not evaluated in Phase 2/3.

Data Monitoring Committee or Other Independent Oversight Committee

The study will utilize an IRC, an internal Pfizer committee that will review data to allow
dose escalation or changes to continuation of specific groups.

An external data monitoring committee (DMC) will be formed and will review cumulative
unblinded data throughout the study.

Statistical Methods

The sample size for Phase 1 of the study is not based on any statistical hypothesis testing.

For Phase 2/3, the VE evaluation will be the primary objective. The VE is defined as
VE = 100 × (1 – IRR), where IRR is calculated as the ratio of the first confirmed COVID-19
illness rate in the vaccine group to the corresponding illness rate in the placebo group. With
assumptions of a true VE of 60% and 4 IAs planned, 164 COVID-19 cases will provide 90%

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