IT HAS been known for many years that transient changes of the tuberculin reaction may occur under a variety of circumstances.
Decrease in the size of the skin reaction may follow measles,1-7 scarlet fever,1,4 infectious mononucleosis,1 pertussis,8 typhoid,9 typhus,10 influenza,11 rubella,12 syphilis,13 varicella,14 and polio.15
More recently, similar changes in the cutaneous tuberculin reactivity have been observed following the administration of vaccines of measles,7,16,17 poliovirus,17,18 yellow fever,17 and influenza14,19 viruses. The mechanism for this suppressive effect is not known.
To our knowledge, the effect of viral vaccines on delayed hypersensitivity reactions other than that of tuberculin has not been studied.
An experiment was carried out to determine the response of the cutaneous reaction to histoplasmin in subjects receiving attentuated measles virus and smallpox virus vaccines. This method in effect created a condition of minimal systemic reaction to a virus infection.
Each of 31 children known to be a positive histoplasmin reactor was randomly assigned to