In 1935, Maurice Brodie, a research assistant at New York University, attempted to produce a formaldehyde-killed polio vaccine from ground-up monkey spinal cords. Brodie tested the vaccine on himself and several of his assistants. and later gave the vaccine to three thousand children, many of whom developed allergic reactions, but none developed immunity to polio. Philadelphia pathologist John Kolmer also claimed to have developed a vaccineine in 1935, but it too produced no immunity and was blamed for causing cases of paralytic polio, nine of them fatal.