Unlike the publicity and doubts surrounding claims of a link between the MMR triple vaccine and autism clinicians are in agreement that evidence exists of a risk, albeit very small, of the MMR vaccination causing ITP. It was reported in The Lancet in March 95 that there was a causal association between ITP and the MMR vaccine with the risk assessed at 1 in 24,000 vaccinations. Findings from this study were consistent with the view that ITP results largely from the rubella component of the vaccine.

The Principal Medical Officer at the Department of Health (UK), points out that this side effect is listed (although not by the name ITP) on the MMR leaflet issued to parents at the time of vaccination. It states "your child may very rarely get a rash of small bruise like spots due to the rubella part of the immunisation about 2 weeks after the MMR. If you see spots like this, consult your doctor. "

In a subsequent study published* in March 2001 in the Archive Diseases in Childhood (a specialist magazine for paediatricians published by the BMA) researchers from the Public Health Laboratory Service and the Royal Free Hospital analysed certain hospital records of children under the age of 5 who were admitted with ITP within 6 weeks of having the MMR vaccination. Combining data from this and the previous study it was calculated that 2 out of 3 cases of ITP that occur within the six weeks after immunisation are caused by the MMR vaccine. Unlike the earlier report, both the measles and rubella components are now considered likely candidates. *2001; 84: 227-229

Children with MMR induced ITP typically have the transient self-limiting form of the disease with moderately low platelet counts and milder symptoms. Generally, no treatment is needed. Importantly, there is clear evidence that those who have already had ITP are at no greater risk of recurrence as a result of the vaccination. There is no evidence that MMR is causally related to chronic, long-lasting childhood ITP.

The risk of ITP developing as a result of the MMR vaccination is now estimated at 1 in 22,300 doses, but this is considerably less than the risk of ITP developing following the illnesses themselves. Measles induced ITP is common, rubella is estimated at 1 in 3000 cases, and even mumps is occasionally associated with ITP. Of course, there are many more serious complications of these diseases than ITP.

Advice from the Association's medical advisors is that the fear of ITP is no reason to avoid vaccination, either for children who have had ITP before or for those who have never had it. Children are much more likely to come to harm from the diseases the vaccine prevents than from the few and rare side effects (such as ITP) associated with the injection.

MMR booster vaccinations

Parents of children who develop ITP as a result of the MMR jab can request a serum test before the booster is due to see if full immunity has been achieved, and if so, the booster jab will not be necessary. If the serology testing suggests that a child is not fully immune against measles, mumps and rubella then a second dose of MMR is recommended by the Dept of Public Health.

The NHS publish information on MMR side effects.

Please note:
Although every effort is made to ensure that the information given on this website is correct and up to date, the Association cannot be held responsible for errors or omissions. Association personnel are not able to give clinical advice, please contact your personal clinician.