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Many factors , ranging from lack of susceptibles ( either through the continued spread of infection until it passes the threshold for herd immunity or reduction in the accessibility of susceptibles through physical distancing measures ) , exponential-looking epidemic curves may first linearize ( replicating the " logarithmic " to " logistic " transition first noted by Pierre-François Verhulst , as noted above ) and then reach a maximal limit .
 person: Pierre-François Verhulst
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Answer:
 person: Pierre-François Verhulst