D-Antigen Unit

[gschadow]

Sanofi uses D-Antigen Units for listing. A reference is forthcoming. We have a request to assign a provisional code with the reference. CBER would confirm the definition of the unit at a later date. There is a certain urgency to this.

[gschadow]

D-Antigen paper attached, contains a reference to original unit paper

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original D-antigen unit description, Lancet 1962

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Proposed symbol: [D'ag'U]

[gschadow]

the definition is good enough.

[gschadow]

Additional input received:

I attached a file with the relevant text from the paper- the reference is included in the text (Beale and Mason, 1962).

In a further publication by Beale AJ and Ungar J (The Lancet, 1962, ii, 805, Potency and stability of combined pertussis, diphteria, tetanus and poliomyelitis (quadruple) vaccine), it is stated that "Standard preparations of all three types of poliovirus have been prepared and assigned a unitage such that a "D-line" of 24 mm. in the test described by Beale and Mason (1962) corresponds to 600 units of D antigen for each type".

Thus, the most accurate definition of D-antigen would be by saying that " A value of 600 units of D antigen per millilitre was historically assigned to an antigen concentrate which gave a line distance of 24 mm under the test conditions outlined by Beale and Mason, 1962 (see attached file)".