M 131
both upon our stock of lymph and the staff of the Institute during this period was very heavy, and it is a great cause for satisfaction that all demands for lymph were at all times fully and promptly met. Naturally the replenishment of our stocks has caused us some concern, and vaccination of calves for the year has been heavy. It is, however, anticipated that the issue during 1934 will be smaller than usual.
During the period of heavy production it was found that the lymph-grinding machine fell heavily behind the supply of pulp offered for grinding, and this, coupled with the fact that no duplicate machine exists, led to the request (which was subsequently granted by Government) that a new machine be provided. This machine is now on order and should be in use during 1934. As it is of a quick grinding type, it should relieve us of a certain amount of anxiety on the score of replacement of stocks.
Certain improvements in the routine of lymph preparation have been instituted. Regular passage through the rabbit is now carried out at definite known intervals, so that the history of all seed used is known and recorded. As it was found that the plate counts of most batches of lymph, even after extended storage, were abnormally high, it was considered advisable to institute routine exposure to room temperature for approximately one week in order to bring down the count to proper limits. While this procedure achieves its purpose satisfactorily a doubt arises as to the preservation of the potency of the lymph, particularly after storage, and until the question is definitely settled it is proposed to decrease the dilution with glycerol-saline by the addition of three times the amount of diluent by weight instead of four times as is at present practised. While this will reduce our production to some extent it should definitely enhance its immunizing property.
Potency tests were carried out as usual on babies in the Alice Memorial Hospital, and our grateful thanks are due to the Medical Director and associated members of the staff for their kindness and co-operation in making this possible. Dr. Annie Sydenham in particular has given much of her time to making the necessary inspection and records.
During the writer's leave in 1934 it is hoped to obtain some data on methods of production of vaccine by growth of the virus in vitro in the hope that by this time methods will have progressed sufficiently to have placed this procedure on a practical basis.
Page 495
Page 496
M 131
both upon our stock of lymph and the staff of the Institute during this period was very heavy, and it is a great cause for satisfaction that all demands for lymph were at all times fully and promptly met. Naturally the replenishment of our stocks has caused us some concern, and vaccination of calves for the year has been heavy. It is, however, anticipated that the issue during 1934 will be smaller than usual.
During the period of heavy production it was found that the lymph-grinding machine fell heavily behind the supply of pulp offered for grinding, and this, coupled with the fact that no duplicate machine exists, led to the request (which was subse- quently granted by Government) that a new machine be pro- vided. This machine is now on order and should be in use during 1934. As it is of a quick grinding type, it should relieve us of a certain amount of anxiety on the score of replacement of stocks.
Certain improvements in the routine of lymph preparation have been instituted. Regular passage through the rabbit is now carried out at definite known intervals, so that the history of all seed used is known and recorded. As it was found that the plate counts of most batches of lymph, even after extended storage, were abnormally high, it was considered advisable to institute routine exposure to room temperature for approximate- ly one week in order to bring down the count to proper limits. While this procedure achieves its purpose satisfactorily a doubt arises as to the preservation of the potency of the lymph, parti- cularly after storage, and until the question is definitely settled it is proposed to decrease the dilution with glycerol-saline by the addition of three times the amount of diluent by weight instead of four times as is at present practised. While this will reduce our production to some extent it should definitely enhance its immunizing property.
Potency tests were carried out as usual on babies in the Alice Memorial Hospital, and our grateful thanks are due to the Medical Driector and associated members of the staff for their kindness and co-operation in making this possible. Dr. Annie Sydenham in particular has given much of her time to making the necessary inspection and records.
During the writer's leave in 1934 it is hoped to obtain some data on methods of production of vaccine by growth of the virus. in vitro in the hope that by this time methods will have pro- Pressed sufficiently to have placed this procedure on a practical
Casis.
Page 495Page 496
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