This 1976 U. S. postage stamp commemorates the sacrifice of Clara Maass of East Orange, who at the age of 25 lost her life in Cuba during experimentation with yellow fever vaccination. A young nurse, Maass volunteered to take part in the vaccination testing. The first time she was bitten by an infectious mosquito she contracted a mild case of the disease, causing doctors to believe she was immune, but a second bite proved fatal. Maass's death convinced people that yellow fever was indeed conveyed by the mosquito. Clara Maass Memorial Hospital in Newark is named in her honor.