To the Editor: A review of recut lung-tissue specimens and published autopsy series from the 1918 influenza pandemic suggests that secondary bacterial pneumonia¹ was an important cause of death, consistent with our preliminary analysis of antemortem blood cultures and the time to death of the patients.² We review here studies that reported more than 10 sterile-site antemortem cultures from adults with pneumonia and those without pneumonia in an extensive archive of articles about the 1918 pandemic in any language (www3.niaid.nih.gov/topics/Flu/1918/bibliography.htm). Bacteria were recovered in only a few blood cultures for patients who had influenza but not pneumonia (mean among all . . .