Blood Clots and Pneumococcal Vaccine: What You Need to Know
Blood clots are not a recognized complication of pneumococcal vaccination. The evidence shows no causal association between pneumococcal vaccines and thrombotic events, unlike certain COVID-19 vaccines where this rare complication has been documented 1.
Key Evidence on Pneumococcal Vaccine Safety
The pneumococcal vaccine has an excellent safety profile with no documented thrombotic complications:
- Most reactions are mild local effects (pain, erythema, swelling) occurring in 28-50% of recipients, resolving within 48 hours 2
- Severe systemic reactions including anaphylaxis are rare, with meta-analysis of 7,531 patients showing no severe anaphylactic reactions 2
- No neurologic disorders, including thrombotic events, have been associated with pneumococcal vaccination 2
- Pneumococcal vaccination has not been causally associated with death among vaccine recipients 2
Important Distinction: COVID-19 Vaccines vs. Pneumococcal Vaccines
The confusion likely stems from well-documented thrombotic complications with certain COVID-19 vaccines, which are completely different from pneumococcal vaccines:
- Vaccine-Induced Immune Thrombocytopenia and Thrombosis (VITT) occurs specifically with COVID-19 vaccines (particularly adenoviral vector vaccines like AstraZeneca), caused by anti-platelet factor 4 antibodies 1
- VITT incidence is 14.9 per million after first COVID-19 vaccine dose, occurring 5-30 days post-vaccination 1
- This mechanism has never been reported with pneumococcal vaccines 2
Rare Case Report Exception
One isolated case report from 2014 described thrombotic thrombocytopenic purpura (TTP) 15 days after pneumococcal vaccination in a 68-year-old woman 3. However:
- This represents a single case report over decades of widespread pneumococcal vaccine use 3
- The temporal association does not establish causation 3
- No subsequent cases or patterns have emerged to support a causal relationship 2
Clinical Bottom Line
When counseling patients about pneumococcal vaccine risks, blood clots should not be mentioned as a recognized adverse event. Focus instead on the actual documented reactions:
- Common: Local injection site reactions (28-50% incidence) 2
- Rare: Severe allergic reactions requiring epinephrine 2
- Contraindication: Previous severe reaction or Arthus-type reaction to pneumococcal vaccine 2
All suspected adverse events must be reported to VAERS at 1-800-822-7967 2.