The ws strain of influenza A virus was the first to be isolated from man (Smith, Andrewes & Laidlaw, 1933) and was propagated successively in ferrets and mice by intranasal infection, and on the chorioallantoic membrane of chick embryos. is unique among human influenza viruses in that it gives rise to variants which are neurovirulent for mice inoculated intracerebrally (Stuart-Harris, 1939; Francis & Moore, 1940). Many subsequent attempts to isolate neurotropic variants from other A0, A1 or A2 human influenza viruses have failed.

It can only be a matter of speculation how such variants as (Stuart-Harris, 1939) might have arisen from . The antigenic constitution of the two strains appears to be identical, but differs from in a number of laboratory properties other than neurotropism (Burnet & Lind, 1951; Hobson 1968). Both the neurotropism and the laboratory markers of breed true on limiting dilution passage in chick embryos, or after plaque purification in tissue cultures of chick embryo fibroblasts.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error