In 1918, scientists had a poor understanding of viruses, which were murderous phantoms too small to see. Although the curtain that concealed the viral world has been pulled open, the tools for curbing a novel pandemic haven’t changed. Nonpharmaceutical interventions—traditional public health measures—are still the only reliable way of slowing contagion until effective treatments or vaccines can be put into play. The only real difference in a hundred years is that face masks are more effective.
