MMR-type vaccine for cattle withdrawn after test fears 15 years ago
By Sarah-Kate Templeton Health Editor
A combined vaccine similar to the controversial MMR jab was withdrawn from
use on cattle because it did not work properly, a leading Scottish vaccine
expert has revealed.
As a cluster of measles cases were reported in an area where parents are
boycotting MMR due to suspected links with autism and bowel disorders, Dr
John March of the government-funded Moredun Research Institute, warned that
vaccines for cattle are tested more thoroughly than jabs for children.
March believes the measles vaccine weakens the immune system and that this
can be problematic when it is given at the same time as other live
vaccines, such as mumps and rubella.
He said it is not known, as yet, whether the MMR vaccine causes autism --
as some experts have claimed -- but he believes there is the 'potential for
'Immuno-suppression can easily be detected and monitored in an individual
animal. With current human vaccine trials this would never be observed,' he
Evidence of a problem with the cattle vaccine has been available for 15
years, but March said the comparison between the cattle and human vaccine
has not been made until now as veterinary scientists and medics were
working in isolation.
A paper published in the scientific journal Veterinary Record in 1987, the
year before the MMR was licensed in this country, showed that when cows
were given a combined cattle measles and pneumonia vaccine the measles part
interfered with the pneumonia component and weakened the immune system.
In his work on animals, March and his colleagues study immune responses to
vaccines over months and years, taking blood samples at regular intervals
to measure whether the immune system is suppressed or modified and for how
March pointed out that in humans, however, blood samples are taken only on
a single occasion, and the results from different children are pooled to
give an average. He said the available data is therefore extremely limited
and the chances of picking up individual reactions small.
'Perhaps only one in 200 children may not be able to handle three live
viruses and these are the ones who become autistic. It is more likely to
happen with three simultaneous live infections. We simply do not know as we
have never done these studies .
'If we look at a similar situation in animals then yes, the measles vaccine
did interfere with the other component. It did affect the immune response.
Although there is this potential in humans, they say it is not going to
happen so they are not going to investigate. '
March's call for more research comes as three children were confirmed as
having measles and a further 22 possible cases are being investigated at
two private nursery schools in South London.
Bill Welsh, chairman of Action Against Autism, said parents would welcome
screening to identify children at risk of an adverse reaction to the MMR
vaccine. He said: 'If multiple vaccines containing live viruses are unsafe
for beasts in the field, why are they being injected directly into the
bloodstreams of our children?'
Dr Claire Bramley of the Scottish Centre for Infection and Environmental
Health defended the vaccine.
'There is no indication of any problem with the measles virus in the MMR
vaccine. The MMR vaccine is as effective in protecting against measles,
mumps, and rubella as when each component is given on its own. '