Public domain
Testing yellow fever serum by injecting it into the brain of a monkey. USPHS (United States Public Health Service) Rocky Mountain Laboratory, Hamilton, Montana
From the collection of Library of Congress. Free to download, adapt and use — no permission needed.
Credit lineTesting yellow fever serum by injecting it into the brain of a monkey. USPHS (United States Public Health Service) Rocky Mountain Laboratory, Hamilton, Montana. 1942-01-01. Vachon, John. Farm Security Administration/Office of War Information Collection, Library of Congress. Public domain.