George Gey successfully cultured the first immortal cell line using cells from Henrietta's cervix in 1951. That immortal cell line has been used extensively in medical research. Because he failed to inform Henrietta and her family about him taking samples of her cells, they did not gain any recognition until many years later.
Scientists used HeLa cells to help develop the vaccine for polio shortly after Henrietta's death in 1952. Scientists were able to run very many tests on the cells because there was an almost unlimited supply of them, and they were highly susceptible to the polio virus.