May 20, 1941
Dear Dr. Heidelberger:
This letter is to confirm our telephone conversation concerning the meeting of the Army Pneumonia Commission at 9:30 a.m. Tuesday, May 27th, at the
Rockefeller Institute. Since you are a resident of New York City you will not receive Travel Orders from the Surgeon-General's office.
In our brief conversation in Nashville you may recall that the question of antipneumococcal immunization came up. As I remember we agreed that the possibilities of prophylactic antipneumococcal vaccination have not been fully explored, particularly from the point of view of an innocuous and perhaps more effective polysaccharide antigen.  It is of course possible to use carefully prepared vaccines, but the disadvantages of these are obvious. However, it does seem possible that if the polysaccharides could be rendered less soluble or immobilized in the tissues a little longer their antigenicity might be improved considerably and at the same time no local or constitutional reaction result. I mention the matter again at this time since it will be discussed at the meeting of the Commission, and your thoughts on the matter and the approach to it are very desirable. It is quite possible that an appropriation for supplies and technical assistance for this project will be approved by the Board.
The advisability of general antipneumococcal immunization is open to question in the light of the work that has been done to date, but immunization in the face of an epidemic may have considerable usefulness, particularly if backed up by adequate epidemiological work.
I would appreciate it if you would draw up a tentative program for the interim investigation of this problem, to include estimates of salaries for technical assistance, for expendable supplies (media, glassware, reagents, etc.) and for durable property if necessary. As far as technicians are concerned the regulations state that they may be employed without civil service status up to not more than 60 days continuous employment during any fiscal year.  If on part time service, the number of hours of employment during any one year cannot be more than require payment of $540.00. Otherwise, technicians must be on civil service status.
Sincerely yours,
Colin M. MacLeod, M.D.