Thrombocytopenia after vaccination

A decrease in platelet count, i.e. thrombocytopenia, occurs after various types of viral diseases, such as measles and rubella. It is also a very rare adverse effect of the MMR vaccination.

The symptoms of thrombocytopenia include

  • bruises
  • nose bleeds
  • small haematomas on the skin

In studies, the incidence of thrombocytopenia following an MMR vaccination has been 1 case per 50,000 recipients.

Treating thrombocytopenia

  • A significant decrease in platelets always requires a physician’s assessment and monitoring.
  • Even if the platelet count drops to a very low level, it usually returns to normal in a few months.

Follow-up vaccinations

When deciding on further vaccinations, the risk of thrombocytopenia after a natural infection must be compared with the risk after vaccination. 

The risk of thrombocytopenia is at least 10 times higher in people with measles or rubella compared to the risk caused by MMR vaccine recipients.

  • A physician will make a decision on follow-up vaccinations if the patient has been diagnosed with thrombocytopenia within six weeks of the first MMR vaccination.
  • This is not an absolute contraindication to further vaccinations.
  • The benefits of the protection afforded by the vaccination against measles and rubella are mostly greater than the risk of thrombocytopenia reoccurrence.

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