The AIDS Vaccine Impasse: Lessons from Jonas Salk and the March of Dimes (Draft)

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unscarred by smallpox resulted from the cowpox lesions on their hands. A
century later, Louis Pasteur did not understand how his rabies vaccine
worked.
Even field trials which show no efficacy at all are a normal part of
the vaccine development process. In the early 1980s, the first generation
of Hemophilus meningitis vaccines did not protect children enrolled in
large trials. But the lack of success stimulated revisions to the design
which ultimately proved effective. Hemophilus vaccines were finally
licensed in the early 1990s and have nearly eliminated the 10 to 15
thousand cases of devastating infant meningitis which used to occur each
year in the U.S.
Predicting AIDS vaccine success or failure in humans is a
speculative exercise: There exist no validated test-tube assays of human
blood nor laboratory animal homologies which can tell us with certainty
whether they will work in people. As with pioneering trials for earlier
vaccines, including polio, the ultimate worth of AIDS vaccines can only be
determined empirically by seeing if humans who receive them experience
reduced occurrence of disease.
A vaccine of only partial efficacy in preventing HIV infection, in
forestalling AIDS, or in reducing contagiousness -- a "single to first
base" -- would be a major tool in slowing an epidemic in which some 40,000
Americans and millions worldwide are becoming newly-infected with HIV each
year. It also could reveal the holy grail of HIV research: the changes in
blood tests following vaccination which would predict protection from HIV
or AIDS or reduced transmissibility to others. Such information would