ACTION OF ULTRAVIOLET LIGHT ON VIRUSES 



161 



different from the hemagglutination curve, which has a pro- 

 tein-like maximum. Perhaps most striking is the fact that, 

 whereas the loss of infectivity followed an inactivation curve 

 somewhere near a one-hit type, the hemagglutinating loss fol- 

 lows a strongly multi-hit type. Tamm and Fluke ])oint out that 



Loss 



of 



Infectivity 



or 



Agglutination 

 Ability 



nfectivity o— 

 Hemagglutination x 



2200 



2400 2600 2800 3000 

 Wavelength (A) 



96 



Agglutination 

 Titer 



«^— -A ^- 



\ 



2803^ 



3200 

 3023 A 



I 2652 A 

 1 





20 



40 

 Dose 



60 

 ( Ergs , 



80 



100 



120 X 10 



Fig. 6.9. Action spectra and dose-effect curves for influenza virus, as taken 

 by Tamm and Fluke (1951). The hemagglutination maximum is clearly in the 

 protein region, whereas the infectivity maximum is more nearly nucleic acid in 

 character. The multi-hit character of loss of agglutinating ability can also be 

 seen. It is both striking and variable. 



this could be exploited for the preparation of vaccines, assuming 

 that the serological behavior follows more the hemagglutination 

 behavior. Ultraviolet inactivation has been successfully applied 

 to produce rabies vaccine by Levinson, Milzer, Shaughnessy, 

 Neal, and Oppenheimer (1945). 



This work shows clearly that the study of action spectra does 

 not yield a monotonous repetition of a nucleoprotein absorption 



