While the thought of a sore arm might seem universal after a shot, the data reveals a fascinating spectrum of common and rare side effects across vaccines, from the widely familiar COVID-19 immunizations to routine childhood shots like the MMR and DTaP.
Key Takeaways
- In the Pfizer-BioNTech COVID-19 vaccine phase 3 trial, 83% of participants aged 16-55 reported local pain at the injection site after dose 1.
- Moderna COVID-19 vaccine trial showed 92.1% of recipients experienced injection site pain after the first dose.
- AstraZeneca COVID-19 vaccine in UK trials reported 70.4% injection site pain in under 65s after first dose.
- Pfizer COVID-19 vaccine caused fatigue in 59.1% after dose 1 in 16-55 group.
- Moderna vaccine: 59.7% fatigue post-dose 1.
- AstraZeneca: 53% fatigue after first dose.
- Anaphylaxis confirmed in 5 cases per million doses of Pfizer COVID-19 vaccine in US early rollout.
- Moderna COVID-19 vaccine anaphylaxis rate 2.5 per million doses.
- J&J/Janssen anaphylaxis 3 per million doses.
- Guillain-Barré Syndrome (GBS) after Janssen COVID-19 vaccine: 15.5 excess cases per million doses in males 50-64.
- AstraZeneca COVID-19 vaccine GBS: 2.49 excess cases per million after first dose.
- Pfizer COVID-19 no significant GBS increase.
- Thrombosis with Thrombocytopenia Syndrome (TTS) after J&J COVID-19: 3.83 per million doses.
- AstraZeneca TTS 8.1 per million first dose in 18-49 females.
- Myocarditis after Pfizer COVID-19: 12.6 per million second doses in males 12-29.
Common vaccine side effects are minor and far less severe than the diseases they prevent.
Mild Local Reactions
- In the Pfizer-BioNTech COVID-19 vaccine phase 3 trial, 83% of participants aged 16-55 reported local pain at the injection site after dose 1.
- Moderna COVID-19 vaccine trial showed 92.1% of recipients experienced injection site pain after the first dose.
- AstraZeneca COVID-19 vaccine in UK trials reported 70.4% injection site pain in under 65s after first dose.
- Janssen COVID-19 vaccine trial indicated 58.6% had pain at injection site post-dose 1.
- Influenza vaccine (Fluarix) in adults caused injection site pain in 35-60% of recipients.
- HPV vaccine (Gardasil 9) trials showed 84.2% of females aged 9-15 reported injection site pain.
- MMR vaccine post-licensure studies found 15-20% redness/swelling at site in children.
- DTaP vaccine in infants led to injection site erythema in 25% after dose 3.
- Hepatitis B vaccine (Recombivax HB) caused soreness at site in 29% of adults.
- Shingles vaccine (Shingrix) reported injection site pain in 77.9% after first dose.
- Pfizer COVID-19 vaccine, 71.6% reported pain after dose 2 in 16-55 age group.
- Moderna vaccine, 91.4% injection site pain post-dose 2.
- AstraZeneca, 64.8% pain after second dose.
- Fluad (adjuvanted flu vaccine) in elderly: 23% pain at site.
- Prevnar 13 pneumococcal vaccine: 20-30% tenderness in toddlers.
- Rotavirus vaccine (RotaTeq): 10-15% injection site reactions in infants.
- Varicella vaccine: 19% redness at site.
- Tdap (Boostrix): 61-75% pain in adults.
- Menactra meningococcal vaccine: 25-41% pain.
- Yellow fever vaccine: 21% local pain.
- Pfizer booster dose: 78% pain in injection site.
- J&J booster: 55% site pain.
- Novavax COVID-19 vaccine trial: 81% pain after dose 1.
- Sputnik V: 65-70% local reactions.
- Sinovac CoronaVac: 20% injection site pain.
- Covaxin: 15% local pain in trials.
- Pfizer pediatric (5-11): 80% pain.
- Moderna pediatric: 85% site pain.
- Bexsero meningococcal B: 83% pain in adolescents.
- Trumenba meningococcal B: 75-85% pain.
Mild Local Reactions Interpretation
While it's comforting to know that the most common vaccine side effect across all brands and diseases is essentially a confirmation that you still possess a functioning nervous system and a healthy immune response, the data clearly shows that getting a shot is statistically more likely to hurt your arm than to hurt you.
Mild Systemic Reactions
- Pfizer COVID-19 vaccine caused fatigue in 59.1% after dose 1 in 16-55 group.
- Moderna vaccine: 59.7% fatigue post-dose 1.
- AstraZeneca: 53% fatigue after first dose.
- Janssen: 37.6% fatigue.
- Shingrix: 45.5% fatigue after dose 1.
- HPV Gardasil 9: 38% fatigue in females 9-15.
- Fluarix flu vaccine: 13-25% fatigue in adults.
- MMR: 5-15% fatigue/malaise in children.
- DTaP: 30% fussiness in infants post-dose.
- Hepatitis B: 10-14% fatigue.
- Tdap Boostrix: 30-40% fatigue.
- Prevnar 13: 20-30% decreased appetite/fatigue.
- Rotarix: 3-6% irritability/fatigue.
- Varicella: 10-15% malaise.
- Menactra: 10-20% fatigue.
- Fluzone HD: 25% fatigue in elderly.
- Pfizer dose 2: 83% fatigue.
- Moderna dose 2: 68% fatigue.
- Novavax: 64% fatigue dose 1.
- Sputnik V: 50-60% fatigue.
- CoronaVac: 10-15% fatigue.
- Covaxin: 20% fatigue.
- Pfizer 5-11: 40% fatigue.
- Bexsero: 50-60% fatigue.
- Trumenba: 40-50% fatigue.
- Pfizer vaccine fever in 16.1% after dose 1 (16-55).
Mild Systemic Reactions Interpretation
It seems that our immune systems, when finally put to work, tend to complain about the overtime with a collective and profound sense of exhaustion, making fatigue the most democratic of vaccine side effects.
Neurological Events
- Guillain-Barré Syndrome (GBS) after Janssen COVID-19 vaccine: 15.5 excess cases per million doses in males 50-64.
- AstraZeneca COVID-19 vaccine GBS: 2.49 excess cases per million after first dose.
- Pfizer COVID-19 no significant GBS increase.
- Influenza vaccine annual GBS risk 1-2 excess per million.
- Shingrix GBS reported in 3 per million doses.
- HPV vaccine GBS claims no causal link, background rate.
- Menactra meningococcal GBS 0.4 per 100,000.
- VAERS Bell's palsy after Pfizer COVID-19: 7.4 per 100,000.
- Moderna Bell's palsy 8.4 per 100,000.
- J&J acute disseminated encephalomyelitis (ADEM) rare reports.
- MMR encephalitis 1 per 3 million doses.
- Oral polio vaccine aseptic meningitis 1 per 2.4 million doses historically.
- Yellow fever vaccine neurotropic disease 0.4-0.8 per 100,000.
- COVID-19 vaccines transverse myelitis ~1-2 per million.
- Pfizer pediatric Bell's palsy no increase.
- AstraZeneca cerebral venous sinus thrombosis (CVST) associated in young women.
- Headache after Pfizer 24.4% dose 1.
- Migraine reports post-COVID vaccines in VAERS elevated.
- Seizures post-DTaP 1 per 14,000 doses in infants.
- Narcolepsy after Pandemrix H1N1 vaccine 1 in 16,000 in Finland.
Neurological Events Interpretation
While all medicines carry some risk, these statistics show that severe neurological side effects from vaccines are remarkably rare events, often measured in single digits per million doses, and are typically dwarfed by the known risks of the diseases they prevent.
Severe Allergic Reactions
- Anaphylaxis confirmed in 5 cases per million doses of Pfizer COVID-19 vaccine in US early rollout.
- Moderna COVID-19 vaccine anaphylaxis rate 2.5 per million doses.
- J&J/Janssen anaphylaxis 3 per million doses.
- MMR vaccine anaphylaxis 1-2 per 100,000 doses.
- DTaP anaphylaxis ~1 per million doses.
- Influenza vaccine anaphylaxis 1.3 per million.
- HPV Gardasil anaphylaxis 2.4 per 100,000.
- Shingrix anaphylaxis rare, <1 per 100,000.
- Hepatitis A vaccine anaphylaxis 1 per million.
- Pneumococcal PCV13 anaphylaxis 1 per 1 million.
- Yellow fever vaccine anaphylaxis 1 per 130,000-1 million.
- Meningococcal MenACWY anaphylaxis ~1 per million.
- Varicella anaphylaxis 1 per million.
- Rotavirus vaccines anaphylaxis <1 per 100,000.
- Tdap anaphylaxis 0.36 per million.
- COVID-19 vaccines overall anaphylaxis 11.1 per million doses (Pfizer/Moderna).
- Egg-allergic patients flu vaccine anaphylaxis risk not elevated.
- Gelatin allergy in MMR anaphylaxis cases ~76% attributable.
- Pfizer booster anaphylaxis 4.4 per million.
- AstraZeneca rare urticaria/anaphylactoid in 1/10,000.
- J&J hypersensitivity reactions 1.6% overall, anaphylaxis rare.
- Bexsero anaphylaxis 1 in 10,000-100,000.
Severe Allergic Reactions Interpretation
While the COVID-19 vaccines raised understandable concern about rare anaphylaxis, their risk window remains in line with many trusted routine shots, offering vital context that the feared 'novel' danger is, reassuringly, rather ordinary.
Thrombotic and Cardiovascular Events
- Thrombosis with Thrombocytopenia Syndrome (TTS) after J&J COVID-19: 3.83 per million doses.
- AstraZeneca TTS 8.1 per million first dose in 18-49 females.
- Myocarditis after Pfizer COVID-19: 12.6 per million second doses in males 12-29.
- Moderna myocarditis 15.1 per million second dose males 18-24.
- Pericarditis post-Pfizer 5.8 per million in males 12-29 after dose 2.
- J&J myocarditis rare, 2 per million.
- Influenza vaccine myocarditis rare background.
- HPV vaccine no increased CV risk.
- Shingrix cardiac events no signal.
- Smallpox vaccine myopericarditis 5-15 per 10,000 in young males.
- COVID-19 vaccines pulmonary embolism reports in VAERS.
- AstraZeneca cerebral venous sinus thrombosis 1.3 per million.
- Arrhythmia post-Pfizer 1.7 per 100,000 in VAERS analysis.
- Stroke reports post-J&J elevated in some cohorts.
- Deep vein thrombosis AstraZeneca 1 per 100,000.
- Myocarditis Moderna booster 10 per million young males.
- Pfizer pediatric myocarditis <1 per million.
- TTS after AstraZeneca second dose lower risk.
- Cardiac arrest reports rare post-vaccination.
- Hypertension transient post-vaccines in some studies.
- Capillary leak syndrome rare after some vaccines.
Thrombotic and Cardiovascular Events Interpretation
When you weigh the vanishingly rare but real risks of conditions like TTS and myocarditis from certain COVID-19 vaccines—often measured in single-digit cases per million—against the staggering, well-documented dangers of the diseases they prevent, it becomes a starkly simple equation of statistical survival.
Sources & References
- Reference 1NEJMnejm.orgVisit source
- Reference 2THELANCETthelancet.comVisit source
- Reference 3FDAfda.govVisit source
- Reference 4CDCcdc.govVisit source
- Reference 5MEDRXIVmedrxiv.orgVisit source
- Reference 6NCBIncbi.nlm.nih.govVisit source
- Reference 7EMAema.europa.euVisit source
- Reference 8PUBMEDpubmed.ncbi.nlm.nih.govVisit source
- Reference 9BMJbmj.comVisit source
- Reference 10GOVgov.ukVisit source