It was touch and go whether Jean Macnamara would be able to work at Melbourne’s Royal Children’s Hospital. When she sought employment there after graduating with a medical degree from the University of Melbourne in the early 1920s, hospital authorities were openly reluctant to hire a woman, telling Macnamara that there weren’t appropriate toilet facilities on the premises. Macnamara ended up getting the position, but it wouldn’t be the last time she faced resistance from the medical community.
A few years later, a polio epidemic hit Melbourne. The disease, which had been on the rise since the late 1800s and had recently caused a devastating outbreak in New York City, was notorious for its effect on children, who, in severe cases, died or were left paralyzed. At the time, not much was known about polio other than that it was a viral disease, says Gareth Williams, an emeritus professor of medicine and dentistry at the University of Bristol and author of the 2013 book Paralysed with Fear: The Story of Polio. Early attempts to create a vaccine had failed and, confusingly, some people seemed to get polio more than once—a phenomenon that went against traditional ideas about immunity.
Collaborating with a colleague, Macfarlane Burnet of the Walter and Eliza Hall Institute, Macnamara began studying blood serum from polio survivors. When the researchers tested this serum, as well as serum from polio-infected monkeys, against different samples of the virus, they found that not every serum sample neutralized every virus sample. The antibodies in the serum were specific to a particular version of the virus, the pair realized: there was more than one type of polio. The finding, published in 1931, was a breakthrough. “Until then, people assumed it was just one virus,” says Williams.
However, the work was dismissed by Simon Flexner, then head of the Rockefeller Institute for Medical Research in New York City. Flexner had struggled to develop a polio vaccine several years earlier, and subsequently declared the task impossible. He maintained until his death in 1946 that there was only one kind of poliovirus, and his influence dissuaded many researchers from following up on Macnamara’s and Burnet’s work.
But in 1949, Johns Hopkins University researchers conclusively demonstrated that there were, in fact, hundreds of strains of poliovirus, which fell into three types. Antibodies to one strain granted immunity against other strains in that type, they showed, but not against strains of another type. This finding was a critical foundation for the trivalent vaccines developed in the 1950s to combat strains of all three types.
By that time, Macnamara had adopted another high-profile cause: the use of myxoma virus against Australia’s economically devastating plagues of invasive rabbits. Despite the approach’s failure in trials during the 1930s, Macnamara lobbied to have researchers try it again. In the 1950s, it worked, killing millions of rabbits, although rabbit populations eventually developed genetic resistance to the virus.
Macnamara’s determined nature often rankled other scientists. But she was also widely admired. In 1935, she was made Dame of the British Empire, and her funeral, following her death in 1968, was attended by many of her former polio patients.