A
US study has re-ignited the debate about the safety of the
MMR vaccine by suggesting it may raise the risk of neurological
problems.
The
MMR vaccine is highly controversial
Leading
experts - who have repeatedly stressed the vaccine is safe
- have expressed doubts about the validity of the study, claiming
it is deeply flawed.
They are concerned that continuing suspicion about the safety
of the vaccine - despite overwhelming scientific evidence
to the contrary - will see vaccination rates dip to levels
which make a measles epidemic more likely.
But UK campaigners, who want single jabs for measles, mumps
and rubella to be made widely available, say the latest research
justifies their continuing belief that MMR is not safe.
The researchers compared the controversial vaccine with another
vaccine given to children to protect them from diphtheria,
tetanus and pertussis (DTP).
They found that the MMR vaccine was associated with a significant
increase in the incidence of serious neurological disorders
when compared to the other vaccine.
The researchers based their findings on an analysis of data
collected by the US Vaccine Adverse Events Reporting System
between 1994 and 2000.
During that time nearly 25 million children were given a first
dose of MMR. Of these, 133 developed a neurological problem
- either autism, mental retardation, a disorder called cerebellar
ataxia or permanent brain damage.
The risk of autism was five times greater in those given MMR
than it was in those given DTP.
Dead vaccine
The research was led by Dr Mark Geier, a geneticist at the
National Institutes of Health.
He suggests that the MMR vaccination programme should continue
- but with a version that contains dead, rather than live
virus material to cut the risk of adverse reaction.
If the live vaccine continues to be used, than parents should
be able to opt for separate single jabs, he says.
Writing in the journal International Pediatrics, he said:
"It is clear that with the potentially globally destructive
effects of natural measles, mumps and rubella infections that
continued vaccination is necessary, but improvements in MMR
vaccine is needed to improve its safety."
A Department of Health spokesman said previous research by
the same authors, using similar methodology, had been carefully
reviewed by the Committee on Safety of Medicines (CSM).
"The advice of the CSM was that this type of analysis cannot
used to determine and compare the incidence of adverse reactions
associated with different vaccinations.
"Therefore, because of serious methodological flaws, the conclusions
of the authors concerning the association between MMR and
DTP vaccine and the outcomes studied cannot be justified."
For instance, he said there were concerns about the way adverse
reactions were reported to the database, and question marks
about the validity of comparing vaccines given to children
at different ages.
"The view of the CSM remains that the available scientific
evidence does not support a causal link between MMR vaccination
and autism. This view is in line with the consensus of several
national and international scientific organisations."
Review call
But Jackie Fletcher, of the campaigning group Jabs, called
on the government to reassess its policy in light of the new
study.
Currently, single dose vaccines for measles, mumps and rubella
are not available on the NHS.
She said similar evidence presented to the Department of Health
by Jabs had been dismissed as "anecdotal and insignificant".
"It is six years since the UK Government and vaccine policy
makes were told of this problem and they have failed to investigate
it properly by setting up a scientific, clinical examination
of the damaged children."
Mrs Fletcher said ministers had also failed to improve the
"inadequate" adverse events surveillance system, or to keep
health professionals fully informed of the debate.
The
MMR vaccine is highly controversial
