§ Mrs. Anne CampbellTo ask the Secretary of State for Health what scientific assessments he has carried out of the differences between the Lister and New York strains of the smallpox vaccine. [50896]
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§ Mr. HuttonThe choice of smallpox vaccine strain took into account expert advice, under the auspices of a specially convened sub-group of the joint committee on vaccination and immunisation (JCVI).
The advice of the JCVI sub-group was that there was no difference between the two strains on scientific grounds. Vaccines based on both strains were considered to have been effective in the past.
However, the JCVI sub-group concluded that there is a greater body of evidence to demonstrate the efficacy of the Lister strain rather than for the New York City Board of Health strain, and that the smallpox vaccine has been challenged in the field more often by the more severe form of smallpox "variola major" with the strain chosen by the UK Government. The JCVI sub-group also recommended that using a different strain of vaccine from that used in the United States offered the greatest safeguard if difficulties arose with the production of either strain ensuring that the alternative strain could act as a fall-back.