Armstrong – Table of Contents

He reported (26) the testing of a group of 293 serums, mostly by his associate Dr. Victor
H. Haas. This group of 293 serums was larger than any previous series reported up to that
point by a single laboratory using monkeys; Armstrong indicated that this was an initial
study with more to follow. He also reported that the results in mice were usually definite,
easily read and reproducible. Preliminary results in the initial group of 293 serums
showed percentages similar to smaller number of serums tested in monkeys: Sixty-five
per cent of serums showed full immunity, 6.5 per cent showed partial immunity and 28.5
per cent showed no immunity. Over succeeding years, as many more serums were
examined, (some derived from established cases of poliomyelitis), it became apparent
that some serums from definite polio patients, did not neutralize the Lansing strain. This
finding reinforced the impression among polio researchers that there was more than one
immunologic type of poliovirus. In 1949 (27), using 14 monkeys, Bodian, Morgan and
Howe established that there were 3 types of poliovirus, designated Types I, II, and III
(named Brunhilde, Lansing, and Leon after the sources from which they were isolated),
and subsequent studies indicated that the Lansing represented the least prevalent strain.
In summary: “The adaptation of the Lansing strain of poliovirus to cotton rats and (white)
mice in 1939 was a major advance in this period, an event which opened the way to
quantitative measurement of virus and neutralizing antibody on a scale that was
impossible to achieve in monkeys. Finally, with the increasing use of freshly isolated
poliovirus strains, a developing awareness of the occurrence of significant strain
differences was created (28).”
Additionally noted in reference to the Lansing strain, Enders, Feller and Robbins
(29) used Lansing strain mouse brain material in adapting poliovirus to grow in human