Safety Data Summary

• In clinical trials, reactogenicity symptoms (side effects that happen within 7 days of getting vaccinated) were common but were mostly mild to moderate.
• Side effects (such as fever, chills, tiredness, and headache) throughout the body were more common after the second dose of the vaccine.
• Most side effects were mild to moderate. However, a small number of people had severe side effects—defined as side effects affecting a person’s ability to do daily activities.
• Although few people in the clinical trials went to the hospital or died, data suggest that people who got the Pfizer-BioNTech vaccine were less likely to have these more serious outcomes compared to people who got the saline placebo.
• CDC will continue to provide updates as we learn more about the safety of the Pfizer-BioNTech vaccine in real-world conditions.

SOURCE: CDC - ttps://www.cdc.gov/coronavirus/2019-ncov/vaccines/different-vaccines/Pfizer-BioNTech.html (April 15, 2021)

Clinical Trial Demographic Information

Clinical trials for the Pfizer-BioNTech vaccine included people from the following racial and ethnic, age, and sex categories:

• 81.9% White
• 9.8% African American
• 4.4% Asian
• <3% other races/ethnicities
• <1% Native Hawaiian or Other Pacific Islander
• <1% American Indian or Alaska Native

Ethnicity

• 2% Not Hispanic or Latino
• 2% Hispanic of Latino
• <1% Not Reported

Age and sex breakdown:

• 50.6% male
• 49.4% female
• 21.4% 65 years and older​

Age

• 9% 16 to 55 years
• 8% 55 years and older
• 4% 65 years and older​
• 3% 75 years and older

The most frequent underlying medical conditions were obesity (35.1%), diabetes (8.4%), and pulmonary disease (7.8%).

SOURCE: CDC - ttps://www.cdc.gov/coronavirus/2019-ncov/vaccines/different-vaccines/Pfizer-BioNTech.html (April 15, 2021)