Skip to main content
. 2021 Apr 20;8:871–879. doi: 10.1016/j.toxrep.2021.04.003

Table 2.

Safety evaluation in humans conducted in randomized clinical trials by applicants on the three vaccines under consideration.

Pfizer BioNTech Moderna Astra-Zeneca
Dose 30 μg of mRNA 100 μg of mRNA 5 × 1010 vp
x 2 doses x 2 doses x 2 doses
No. subjects 21,720 (vaccine group) 15,185 (vaccine group) 12,021 (vaccine group)
21,728 (placebo) 15.166 (placebo) 11,724 (placebo)
Age groups 16-55 and >55 years ≥18 years 18-55, 56-69, ≥70 year
Follow-up period ≥ 2 months (50.6% of individuals) 63 days 55.6 days
(median after 2nd dose) (median, 50.6% after 2nd dose) (median after 2nd dose) (median after 2nd dose)
Local effects Injection site pain (∼80%) Injection site pain (83-88%) Tenderness (75%)
(Reactogenicity in the vaccine group) Redness and swelling (<10%) Erythema (<9%) Pain (54%)
Lymphadenopathy (0.4%) Swelling/induration (<12%) Redness (<3%)
Lymphadenopathy (<14%) Warmth (<18%)
Itch (<7%)
Swelling or induration (<3%)
Lymphadenopathy (0.3%)
Onset after vaccination 1-3 days 1-2 days <7 days
Duration 1-2 days (median) 1-3 days 3.3 days (mean)
Local effects persisting > 7 days 3.8% (vaccine group)
1.3% (placebo)
Lymphadenopathy, pain
Systemic reactions Vaccine group (84.1%) Vaccine group (86%)
(overall data) Placebo group (53.5%) Placebo group (71.7%)
(after any dose) (for any local and systemic adverse events, after any dose)
Systemic adverse reactions Fatigue (<60%) Fatigue (<66%) Fatigue (62%)
(Reactogenicity in the vaccine group) Headache (<50%) Headache (<59%) Headache (57%)
Myalgia and chills (30%) Myalgia (<58%) Muscle pain (49%)
Arthralgia (20%) Arthragia (<43%)
Fever (≤16%) Fever (<16%) Feverishness (9%)
Nausea (0.8%) Nausea/vomiting (<19%) Nausea (22%) and vomiting (2%)
Chills (<45%) Malaise (44%)
Onset after vaccination 7 days after 1st or 2nd dose 1-2 days after any dose ≤ 7 days of any dose
Duration 1-2 days (median) 2.8 days (mean)
Any adverse events (overall data) Vaccine group (26.7%)
Placebo group (12.2%)
Adverse events (imbalanced) Appendicitis (8/4, vaccine/placebo) Hepatobiliary disorders (15/3, vaccine/placebo) (mainly cholelithiasis and cholecystitis) Nervous System Disorders (headache, lethargy, migraines, somnolence, dizziness)
Biliary events (14/5, vaccine/placebo)
None vaccine-related None vaccine-related (chance)
  • Vaccine group (<12%)

  • Placebo group (<8%)

Serious adverse events (overall data) Vaccine group (0.6%, 56 cases) Vaccine group (16 cases) Vaccine group (0.8 %)
Placebo group (0.6%, 53 cases) Placebo group (10 cases) Placebo group (1.1 %)
Serious adverse events Bell’s paralysis Bell’s paralysis Bell’s paralysis
  • Vaccine group (n = 4)

  • Placebo group (n = 0)

  • Vaccine group (n = 3)

  • Placebo group (n = 1)

  • Vaccine group (n = 3)

  • Placebo group (n = 3)

Cerebrovascular accidents Paraesthesia, hypoesthesia and muscular weakness (not imbalanced):
Embolic strokes
Transient ischaemic attack
Deep vein thrombosis
  • Vaccine group (n = 3, 2, 1, 2)

  • Placebo group (n = 1, 0, 0, 0)

  • Vaccine group (0.47%)

  • Placebo group (0.65%)

Anaphylaxis Vaccine group (n = 2) Vaccine group (n = 1) Vaccine group (n = 1) (not treatment-related)
Placebo group (n = 1) (not treatment-related) Placebo group (n = 1) (without temporal relation with injection)
Deaths Vaccine group (n = 2) Vaccine group (n = 6) Vaccine group (n = 2)
Placebo group (n = 4) Placebo group (n = 7) Placebo group (n = 4)
(none treatment-related) (none treatment-related) (none treatment-related)
Ongoing pivotal studies (long-term events) 2-year follow-up 2-year follow-up 1-year follow-up