The Term "viral hepatitis," as commonly used, applies to 2 diseases that are clinically quite similar but virologically, immunologically, and epidemiologically distinct. These diseases are hepatitis-A (formerly in-fectious hepatitis) and hepatitis-B (formerly serum hepatitis). Any other viral infection that affects the liver, producing an inflammatory response or "hepatitis" is not customarily included under the term viral hepatitis.
Immune serum globulin is highly effective protection against the clinical manifestations of hepatitis-A but ineffective for hepatitis-B. Therefore, accurate diagnosis of the kind of viral hepatitis, insofar as is possible with methods presently available, is crucial to the effective use of immune serum