234 MODERN BIOLOGIC THERAPEUSIS 



pollen of grasses, notably timothy, rye, red top, 

 June grass, etc. ; while the autumnal form is in- 

 duced by the pollen of ragweed, golden-rod, In- 

 dian corn, etc. 



TIME TO VACCINATE 



It is highly desirable that the treatment be 

 a strictly prophylactic one, although encourag- 

 ing results have been obtained with active im- 

 munization when carried out after the disease 

 was already developed. Since it is desirable 

 that a maximum immunity be established before 

 the hay fever season sets in, it is recommended 

 that the prophylactic inoculations be given at 

 least 8 to 10 weeks before the time for the an- 

 nual onset. If this is not possible, prophylactic 

 treatment may be begun at any time before the 

 onset of the disease or even after the disease 

 has started; using longer intervals between in- 

 jections to avoid severe reactions, in case the 

 patient is already suffering with hay fever. 



Caution In the early stages of immunization 

 it is possible by an overdose to induce a severe 

 attack of hay fever lasting nearly 24 hours. In 

 the later stages, however, this has not been ob- 

 served. Therefore, it is important to follow 



