HC Deb 27 May 1919 vol 116 c1055W
Mr. WATERSON

asked whether the strain of lymph obtained some years ago and forming the source of the lymph at present used at the National Vaccine Establishment was originally derived from small-pox matter; and if he will say how and where it was obtained?

Dr. ADDISON

I am not aware of the history of the strain prior to its being tested and taken into use in 1907.