After the trial endpoints were achieved (meaning that the vaccine had been proven safe and effective according to the pre-established trial protocol), it would be unethical to maintain bliding given the existence of the pandemic and the availability of a proven safe and effective vaccine.
Unblinding began after EUA was issued 2020-12-11 and was phased over a period of months (see section 6.1 of the package insert)
From the first dose to 30 days after the second dose in ages 16+, there were 3 deaths in the vaccine group and 5 in the placebo group.
Source: "Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine through 6 Months", Supplementary Appendix, Table S3 https://www.nejm.org/doi/suppl/10.1056/NEJMoa2110345/suppl_file/nejmoa2110345_appendix.pdf (2021-11-04)
From the first dose to unblinding, there were 15 deaths in the vaccine group (including 1 involving COVID-19) and 14 deaths in the placebo group (including 2 involving COVID-19).
Source: "Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine through 6 Months", Supplementary Appendix, Table S4
During the open-label period, there were 3 deaths in the vaccine group and 2 in the placebo group (who had received the vaccine after unblinding).
Source: "Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine through 6 Months"
This brings the total to 18 vs 16.
"None of these deaths were considered to be related to BNT162b2 by the investigators."
Some conspiracists will point to the second or 3rd figure above to suggest that "more people died in the vaccine group", which is true but irrelevant. The difference is not statistically significant in a group of 43,847 participants.
The absolute rate reduction (or ARR, a popular measure of efficacy for conspiracists) on 18 vs 16 in a group of 43,847 is 0.0045%. Conspiracists commonly claim that a 1% ARR in COVID-19 for vaccinated individuals is too small to be meaningful. An ARR of 0.0045 is 222 times smaller!
To believe that the numbers in Table S4 prove that the vaccine causes cardiac arrest or arteriosclerosis, you would also have to believe that a placebo can somehow cause heart attack, (myocardial infarction), multiple organ dysfunction syndrome, and pneumonia.
See: Source: "Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine through 6 Months", Supplementary Appendix, Table S4
From dose 1 to unblinding, there were 268 participants with serious adverse events in the vaccine group, and 268 participants with serious adverse events in the placebo group. (see the section "Serious Adverse Events" in the package insert).
This is a good reminder that "adverse events" are not the same as "side effects" and may be (and usually are) entirely unrelated to vaccination. The fact that there is the same number of serious adverse events in both groups suggests that the number of serious adverse events that were causally related to vaccination was probably very small or none.
The trial protocol lists the study interventions: 2 vaccine candidates and a "saline placebo", described further as "Normal saline (0.9% sodium chloride solution for injection).
Page 45/46: https://cdn.pfizer.com/pfizercom/2020-11/C4591001_Clinical_Protocol_Nov2020.pdf
"The participants were randomly assigned in a 1:1 ratio to receive two 30-μg intramuscular injections, 21 days apart, of BNT162b2 (0.3 ml volume per dose) or saline placebo."
Pfizer trial paper:
2020-12-11 - FDA Issues Emergency Use Authorization (EUA) for Pfizer-BioNTech COVID-19 Vaccine age 16+
2021-05-10 - FDA Issues EUA for adolescents age 12-15
2021-08-23 - FDA Full Approval Granted for Pfizer-BioNTech COVID-19 for age 16+ 2-dose primary series. (note: the same vaccine remains under emergency use authorization for age 12-15)
2021-09-22 - FDA authorizes booster dose for certain populations 6 months after completion of primary series.
2021-10-29 - FDA Issues EUA for children age 5 to 11 (lower dose than age 12+)
2021-11-19 - FDA authorizes boosters for all 18+
2022-01-03 - FDA authorizes boosters for all 12+ and certain immunocompromized children age 5-11
2022-03-29 - FDA authorizes second booster dose for age 50+ and immunocompromized
2022-05-17 - FDA authorizes booster for age 5-11
2022-06-17 - FDA authorizes 3-dose primary series for 6 months through 4 years of age
2022-08-31 - FDA authorizes bivalent vaccine for use as booster dose for age 18+
2022-10-12 - FDA authorizes bivalent booster for age 5-17
2022-12-08 - FDA authorizes bivalent booster for 6 months through 4 years of age
FDA Main page for Pfizer-BioNTech COVID-19 Vaccine
Comirnaty Package Insert (purple cap)
https://www.fda.gov/media/151707/download (July 2022)
Comirnaty Package Insert (gray cap)
https://www.fda.gov/media/154834/download (July 2022)
Note: the package inserts above contain extensive information about the trials. Ingredients are listed on page 19 and 20 (purple cap) and page 17 (grey cap).
Note: Purple cap refers to the original formulation that requires dilution and lasts 1 month in refrigerator at 2°C to 8°C. Gray cap refers to a newer formulation that does not require dilution and lasts 10 weeks in refrigerator at 2°C to 8°C.
Note: Package inserts are available only for approved vaccines and uses, and some information may not apply to vaccines (such as the bivalent vaccine) or uses (in younger ages or as a booster) that are under emergency use authorization.
The Phase 2/3 trial had 21926 participants age 16+ in the vaccine group and 21921 participants age 16+ in the placebo group. (see section 6.1 in the package insert)
Phase 1 Trial paper: Safety and Immunogenicity of Two RNA-Based Covid-19 Vaccine Candidates
Phase 2/3 Trial paper: Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine
Trial paper: Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine through 6 Months
About Emergency Use Authorization
Differences between EUA and Full Authorization