DURING the American occupation of Japan at the end of World War II, and during the Korean conflict, some of our American military personnel contracted smallpox.1 The unique situation was that these servicemen had been vaccinated against the disease and possessed records showing "successful" vaccination.
Epidemiologic investigations revealed that many of these so-called vaccinated soldiers' records showed "immune reaction," "no reading," "no reaction," or "no take." The term "immune" reaction should never be considered as evidence of a successful vaccination. While the phrase is used by some physicians when they see no physical signs at the site of inoculation, a negative reaction is more likely the result of improper preparation of the site of vaccination, a vaccine that has lost its potency (because of being outdated or more probably due to improper storage), or faulty technique in the actual vaccine process. The best clinical evidence seems to indicate that,