Complement-fixing Antibodies to Type 2 (lansing) Poliomyelitis Virus in a Normal Population of a Siybtropical Area* by Natan

Following the adaptation of the MEF1 strain of poliomyelitis virus to infant mice, Casals, Olitsky, and Anslow (1) were able to prepare from the central nervous system of these mice an antigen for the detection of complementfixing (c-f) antibodies to Type 2 poliomyelitis virus (2). Thus, another parameter different from the neutralizing antibody test, has been added for measuring poliomyelitis infection in man. I t was felt that in addition to being another measure of "immunity," c-f antibodies might perhaps prove to differ from neutralizing antibodies in their persistence in man. And, if this were true, determinations of both antibodies might indicate more precisely the time of exposure to poliomyelitis virus. This paper deals with: (a) The age distribution of c-f antibodies to Type 2 poliomyelitis virus in a normal population of a subtropical area. (b) The correlation, if any, between c-f and neutralizing antibodies to the same immunological type of virus. (c) The fate of c-f antibodies in the same individuals in the course of an 18 month period. In order to investigate these problems, sera previously collected in 1950 in the vicinity of Cairo, Egypt, have been studied? Although poliomyelitis epedemics have not been reported in the native population in Cairo, the disease is endemic and Paul et al. (3, 4) have commented in two previous reports on the large number of infantile cases seen at one local children's hospital. In the population of this area, neutralizing antibodies to all three immunological types of poliomyelitis virus were acquired early in life indicating that virtually all children above the age of 3 had been exposed (4). The almost universal presence of antibodies in those older than 3 years partially explains the infantile nature of the disease in Cairo. Because virtually all the population