INTRADERMAL VERSUS SUBCUTANEOUS IMMUNIZATION OF MONKEYS AGAINST POLIOMYELITIS.

1. The introduction of considerable amounts of living, active poliomyelitis virus into the skin and subcutaneous tissue of monkeys protects the animals against intracerebral inoculations of similar virus material. 2. The degree of protection conferred by intradermal is greater than by subcutaneous injection. 3. During intradermal and subcutaneous inoculations, no local or general pathological signs were observed. 4. The degree of protection produced by the immunization methods used is not absolute, since a percentage of the inoculated monkeys respond to intracerebral injections of highly potent virus. 5. The sera of the animals inoculated intradermally or subcutaneously neutralized poliomyelitis virus in vitro, irrespective of the result of intracerebral inoculation, in all except one instance. 6. The power of the serum of treated monkeys to neutralize virus in vitro is a more delicate test of immunity than is the intracerebral inoculation.