Final answer:
The claim that a child dies immediately after receiving plague serum is false. Plague serums are used for treating the plague, and with early and appropriate antibiotic treatment, chances of survival increase significantly.
Step-by-step explanation:
The statement that a child dies immediately after receiving plague serum is false. Plague serums or antibiotics are intended to treat the infection, although the effectiveness depends on several factors including the stage of the disease when treatment begins. For instance, septicemic plague, which is an advanced form of plague with a very high mortality rate even with treatment, enters the bloodstream and can lead to death rapidly without timely and appropriate treatment. However, for individuals treated with antibiotics during the early stages of any form of plague, the chances of survival can significantly increase.
Historical accounts show that during the medieval plague epidemics, not every exposed individual died; survival rates varied based on several factors such as age, general health, and the form of the plague. Evidence from medieval epidemics also reveals heterogeneous immunological responses to the Yersinia pestis pathogen among those who were exposed.