§ Mrs. EwingTo ask the Secretary of State for Health when his Department received the Joint Committee on Vaccination and Immunisation's review of the abstract presented to the American Association of Immunologists and Federation of American Societies for Experimental Biology meeting in San Francisco in 1998 by Dr. V. K. Singh on autism and the MMR vaccine; and what the conclusions of this review were. [149343]
§ Yvette Cooper[holding answer 8 February 2001]: The abstract by Dr. V. K. Singh entitled "Positive titers of measles and measles-mumps-rubella ( MMR) antibody are related to myelin basic protein autoantibody in autism", which he had forwarded to the annual meeting of the American Association of Immunologists/Federation of American Societies for Experimental Biology held in San Francisco on 22 April 1998, was considered by the joint committee on vaccination and immunisation (JCVI) at its meeting held in October 1998.
The JCVI concluded that the abstract did not provide any information to alter its views on the safety of MMR vaccine.
§ Mr. HammondTo ask the Secretary of State for Health what seroconversion rates occur with MMR in relation to(a) measles, (b) mumps and (c) rubella after (i) the first (ii) the second dose. [153674]
§ Yvette CooperTaking seroconversion to mean the percentage of children with detectable antibodies against that infection shortly after vaccination, the usual proportion of individuals with detectable antibodies after the first dose of measles mumps rubella (MMR) vaccine is as follows:
- Measles 95–99 per cent.
- Mumps 90–95 per cent.
- Rubella nearly 100 per cent.
However, the proportion of children with detectable antibodies against infection declines over time so that just before the age of school entry the proportions are lower. The proportion of children with detectable antibodies some years after MMR correlates much better with the actual efficacy of the vaccines (that is the ability to protect against the disease) and is as follows:
- Measles around 90 per cent.
- Mumps around 85 per cent.
- Rubella around 99 per cent.
The second dose of MMR vaccine, given just before school entry, boosts the proportions of children with detectable antibody for each of the three diseases to around 99 per cent. for measles and mumps and virtually 100 per cent. for rubella. Although antibody levels do decline after the second dose of MMR vaccine, the vaccine's clinical efficacy against each of the diseases after the second dose is 99–100 per cent. This shows the importance of children receiving both doses of MMR vaccine.