Adverse Reaction Overview
The safety of Pfizer-BioNTech COVID-19 Vaccine was evaluated in participants 16 years of age and older in two clinical studies conducted in the United States, Europe, Turkey, South Africa, and South America. Study BNT162‑01 (Study 1) enrolled 60 participants, 18 through 55 years of age. Study C4591001 (Study 2) enrolled approximately 44,000 participants, 12 years of age or older.
In Study 2, a total of 21,720 participants 16 years of age or older received at least one dose of Pfizer-BioNTech COVID-19 Vaccine and a total of 21,728 participants 16 years of age or older received placebo.
At the time of the analysis of Study 2, a total of 19,067 (9,531 Pfizer-BioNTech COVID-19 Vaccine and 9,536 placebo) participants 16 years of age or older were evaluated for safety 2 months after the second dose of Pfizer-BioNTech COVID-19 Vaccine.
The safety evaluation of participants in Study 2 is still ongoing. Participants were monitored for solicited local and systemic events, and use of antipyretic medication after each vaccination. Participants continue to be monitored for unsolicited adverse events, including serious adverse events up to six months after the last vaccine dose (see CLINICAL TRIALS section).
The most frequent adverse reactions in a subset (n=8183) of participants 18 years of age and older, who received the vaccine and comprised a subset of the safety population monitored for reactogenicity with an electronic diary were:, injection site pain ( 84.1%), fatigue (62.9%), headache (55.1%), muscle pain (38.3%), chills (31.9%),joint pain (23.6%) and fever (14.2%) and were usually mild or moderate in intensity and resolved within a few days after vaccination.
Clinical Trial Adverse Reactions
Clinical trials are conducted under very specific conditions. The adverse reaction rates observed in the clinical trials, therefore, may not reflect the rates observed in practice and should not be compared to the rates in the clinical trials of another drug. Adverse reaction information from clinical trials may be useful in identifying and approximating rates of adverse drug reactions in real-world use.
Tables 2 through 5 present the frequency and severity of solicited local and systemic reactions, respectively, within 7 days following each dose of Pfizer-BioNTech COVID-19 Vaccine and placebo in the subset of participants 18 years of age and older (n=8183) in the safety population who were monitored for reactogenicity with an electronic diary.
Table 2: Study 2 – Frequency of Solicited Local Reactions Within 7 Days After Each Dose – Participants 18-55 Years of Age (Reactogenicity subset Safety Population*#)- a
- N = Number of participants reporting at least 1 yes or no response for the specified reaction after the specified dose.
- b
- Any local reaction: any redness >2.0 cm, any swelling >2.0 cm, or any pain at the injection site
- c
- Severe: >10.0 cm
- d
- Severe: prevents daily activity
- *
- Randomized participants who received at least 1 dose of the study intervention
- #
- Five participants were between 16 and 17 years of age
|
Local Reaction | Dose 1 | Dose 2 |
---|
Pfizer-BioNTech COVID-19 Vaccine Na=2291 % | Placebo Na=2298 % | Pfizer-BioNTech COVID-19 Vaccine Na=2098 % | Placebo Na=2103 % |
---|
Redness |
Anyb | 4.5 | 1.1 | 5.9 | 0.7 |
Severec | 0.3 | 0.2 | 0.5 | 0 |
Swelling |
Anyb | 5.8 | 0.5 | 6.3 | 0.2 |
Severec | 0.2 | 0.1 | 0.3 | 0 |
Pain at the Injection Site |
Anyb | 83.1 | 14.0 | 77.8 | 11.7 |
Severed | 1.0 | 0.1 | 1.2 | 0 |
Any local reactionb | 83.6 | 14.7 | 78.1 | 12.2 |
Table 3: Study 2 – Frequency of Solicited Systemic Events Within 7 Days After Each Dose – Participants 18-55 Years of Age (Reactogenicity subset Safety Population*#)- a
- N = Number of participants reporting at least 1 yes or no response for the specified reaction after the specified dose.
- b
- Any systemic event: any fever ≥38.0°C, any fatigue, any vomiting, any chills, any diarrhea, any headache, any new or worsened muscle pain, or any new or worsened joint pain
- c
- Severe: prevents daily activity
- d
- Severe: requires intravenous hydration
- *
- All randomized participants who received at least 1 dose of the study intervention
- #
- Five participants were between 16 and 17 years of age
|
Systemic Event | Dose 1 | Dose 2 |
---|
Pfizer-BioNTech COVID-19 Vaccine Na=2291 % | Placebo Na=2298 % | Pfizer-BioNTech COVID-19 Vaccine Na=2098 % | Placebo Na=2103 % |
---|
Fever |
≥38.0°C | 3.7 | 0.9 | 15.8 | 0.5 |
>38.9°C | 0.3 | 0.2 | 1.2 | 0.1 |
Fatigue |
Any | 47.4 | 33.4 | 59.4 | 22.8 |
Severec | 1.4 | 0.5 | 4.6 | 0.7 |
Headache |
Any | 41.9 | 33.7 | 51.7 | 24.1 |
Severec | 1.0 | 0.8 | 3.2 | 0.7 |
Chills |
Any | 14.0 | 6.4 | 35.1 | 3.8 |
Severec | 0.4 | 0.1 | 2.1 | 0 |
Vomiting |
Any | 1.2 | 1.2 | 1.9 | 1.2 |
Severed | 0 | 0 | 0.2 | 0 |
Diarrhea |
Any | 11.1 | 11.7 | 10.4 | 8.4 |
Severed | 0.1 | 0.0 | 0.2 | 0.0 |
New or worsened muscle pain |
Any | 21.3 | 10.8 | 37.3 | 8.2 |
Severec | 0.6 | 0.1 | 2.2 | 0.1 |
New or worsened joint pain |
Any | 11.0 | 6.0 | 21.9 | 5.2 |
Severec | 0.2 | 0 | 1.0 | 0.2 |
Any systemic eventb | 67.1 | 54.1 | 74.2 | 38.2 |
Use of antipyretic or pain medication | 27.8 | 14.4 | 45.0 | 12.6 |
Table 4: Study 2 – Frequency of Solicited Local Reactions Within 7 Days After Each Dose – Participants 56 Years of Age and Older (Reactogenicity subset Safety Population*)- a
- N = Number of participants reporting at least 1 yes or no response for the specified reaction after the specified dose.
- b
- Any local reaction: any redness >2.0 cm, any swelling >2.0 cm, or any pain at the injection site
- c
- Severe: >10.0 cm
- d
- Severe: prevents daily activity
- *
- Randomized participants who received at least 1 dose of the study intervention
|
Local Reaction | Dose 1 | Dose 2 |
---|
Pfizer-BioNTech COVID-19 Vaccine Na=1802 % | Placebo Na=1792 % | Pfizer-BioNTech COVID-19 Vaccine Na=1660 % | Placebo Na=1646 % |
---|
Redness |
Anyb | 4.7 | 1.1 | 7.2 | 0.7 |
Severec | 0.2 | 0.1 | 0.5 | 0.1 |
Swelling |
Anyb | 6.5 | 1.2 | 7.5 | 0.7 |
Severec | 0.1 | 0 | 0.2 | 0.1 |
Pain at the Injection Site |
Anyb | 71.1 | 9.3 | 66.1 | 7.7 |
Severed | 0.2 | 0 | 0.5 | 0 |
Any local reactionb | 72.1 | 10.4 | 66.9 | 8.5 |
Table 5: Study 2 – Frequency of Solicited Systemic Events Within 7 Days After Each Dose – Participants 56 Years of Age and Older (Reactogenicity subset Safety Population*)- a
- N = Number of participants reporting at least 1 yes or no response for the specified reaction after the specified dose.
- b
- Any systemic event: any fever ≥38.0°C, any fatigue, any vomiting, any chills, any diarrhea, any headache, any new or worsened muscle pain, or any new or worsened joint pain
- c
- Severe: prevents daily activity
- d
- Severe: requires intravenous hydration
- *
- All randomized participants who received at least 1 dose of the study intervention
|
Systemic Event | Dose 1 | Dose 2 |
---|
Pfizer-BioNTech COVID-19 Vaccine Na=1802 % | Placebo Na=1792 % | Pfizer-BioNTech COVID-19 Vaccine Na=1660 % | Placebo Na=1646 % |
---|
Fever |
≥38.0°C | 1.4 | 0.4 | 10.9 | 0.2 |
>38.9°C | 0.1 | 0.1 | 0.3 | 0.1 |
Fatigue |
Any | 34.1 | 22.6 | 50.5 | 16.8 |
Severec | 0.1 | 0.2 | 2.8 | 0.1 |
Headache |
Any | 25.2 | 18.1 | 39.0 | 13.9 |
Severec | 0.1 | 0.2 | 0.5 | 0.2 |
Chills |
Any | 6.3 | 3.2 | 22.7 | 2.8 |
Severec | 0 | 0.1 | 1.0 | 0 |
Vomiting |
Any | 0.5 | 0.5 | 0.7 | 0.3 |
Severed | 0 | 0 | 0.1 | 0 |
Diarrhea |
Any | 8.2 | 6.6 | 8.3 | 6.0 |
Severed | 0.2 | 0.1 | 0.1 | 0.2 |
New or worsened muscle pain |
Any | 13.9 | 8.3 | 28.7 | 5.3 |
Severec | 0.1 | 0.2 | 1.0 | 0.1 |
New or worsened joint pain |
Any | 8.6 | 6.1 | 18.9 | 3.7 |
Severec | 0.1 | 0.1 | 0.4 | 0.1 |
Any systemic eventb | 49.0 | 37.9 | 64.5 | 28.2 |
Use of antipyretic or pain medication | 19.9 | 11.9 | 37.7 | 9.8 |
Unsolicited Adverse Events
No deaths related to the vaccine were reported in the study.
Serious Adverse Events
In Study 2, in participants 16 to 55 years of age (Pfizer-BioNTech COVID-19 Vaccine = 10,841,
placebo = 10,851), serious adverse events from Dose 1 through 30 days after Dose 2 were reported by 0.4% of participants and by 0.3% of participants who received at least 1 dose of Pfizer-BioNTech COVID-19 Vaccine or placebo, respectively. In Study 2, in participants 56 years of age and older (Pfizer-BioNTech COVID-19 Vaccine = 7960, placebo = 7934), serious adverse events were reported by 0.8% of participants and by 0.6% of participants who received at least 1 dose of Pfizer-BioNTech COVID-19 Vaccine or placebo, respectively.
Non-Serious Adverse Events
Overall in Study 2, in which 10,841 participants 16 to 55 years of age received Pfizer-BioNTech COVID-19 Vaccine and 10,851 participants received placebo, non-serious adverse events from Dose 1 through 30 days after Dose 2 were reported in 29.3% of participants who received Pfizer-BioNTech COVID-19 Vaccine and 13.2% of participants in the placebo group, for participants who received at least 1 dose. Overall in Study 2, in which 7960 participants 56 years of age and older received Pfizer-BioNTech COVID-19 Vaccine, non-serious adverse events within 30 days were reported in 23.8% of participants who received Pfizer-BioNTech COVID-19 Vaccine and 11.7% of participants in the placebo group, for participants who received at least
1 dose. It was reported in the study that lymphadenopathy had occurred. From Dose 1 through 30 days after Dose 2, reports of lymphadenopathy were imbalanced with notably more cases in the Pfizer‑BioNTech COVID-19 Vaccine group (64) vs. the placebo group (6), which is plausibly related to vaccination. There were no other notable patterns or numerical imbalances between treatment groups for specific categories of non-serious adverse events (including other neurologic or neuro-inflammatory, and thrombotic events) that would suggest a causal relationship to Pfizer‑BioNTech COVID-19 Vaccine.
Post-Market Adverse Reactions
Severe allergic reactions, including anaphylaxis, and hypersensitivity reactions (e.g., rash, pruritus, urticaria, angioedema) have been reported following Pfizer-BioNTech COVID-19 Vaccine during mass vaccination outside of clinical trials.
Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to product exposure. They are included because: a) they represent reactions that are known to occur following immunizations generally; b) they are potentially serious; or c) on the basis of their frequency of reporting.
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