When the COVID-19 pandemic began, there was never a debate over whether there would be a vaccine, only when.

Less than a year in, there are already several viable vaccines being tested — the result of a truly remarkable research effort.

 But this success would not be possible without the many, many scientists who have built up our knowledge of vaccines over time.

One of those scientists was Helen Cassandra Plummer of Hartland, NB, Mount Allison Class of 1918.

Known to her classmates as Plum, Plummer graduated at a time when vaccine science was still in its infancy. She had the highest average among the graduating class, earning honours in physics; served as class vice-president; and was the 1918 valedictorian. Delivered four years into a brutal war with, as yet, no end in sight, Plummer’s valedictory address called on her classmates to focus on the positive changes the war was having on society and invited them to continue the good work that had begun. 

“A great change has taken place in the position of women,” she noted as one example. “Because women have shown that they are capable of rising to meet an emergency, and of fulfilling any task put before them, they hold today a different position in the State from that occupied before the war.”

After graduation, Plummer taught high school for a year in Quebec, then, in 1920, earned her Master of Arts from Columbia University, where she completed advanced work in physics. She joined the Mount Allison faculty for a short time after graduating from Columbia, then taught at a high school in Massachusetts before accepting the position that would define the rest of her career — an appointment as a medical researcher on the staff of the Connaught Laboratory at the University of Toronto. 

Plummer joined the Connaught Laboratory in 1927. The Laboratory opened in 1914 to produce an antitoxin used to treat diphtheria and remained part of UofT until 1972. Along the way it was home base to Frederick Banting and Charles Best and became a key site for research on and production of insulin; was used to produce tetanus antitoxin for Canadian soldiers in both the First and Second World Wars; and played key roles in researching and treating scarlet fever, smallpox, polio, typhus, rabies, and influenza, among many other accomplishments.

Plummer conducted research at the Connaught Lab and also taught in the School of Hygiene and Preventive Medicine at the university, eventually becoming an associate professor. She earned her PhD from University of Toronto in 1934.  

In the 1930s, Plummer worked closely with colleague Dr. Frieda Fraser in research on streptococcus infections, in particular focusing on understanding and treating scarlet fever.

As the threat of war loomed in the late 1930s, Plummer’s focus turned to work on treatments to prevent and treat tetanus and gangrene. By 1942 she and colleague Dr. Edith Taylor were leading the production of large quantities of tetanus toxoid for a preventative vaccine for all members of the armed forces. She was also associated with the development of the TABT vaccine, used to immunize soldiers against tetanus as well as typhoid. Post-war the tetanus toxoid was added to an existing diphtheria-pertussis vaccine, a precursor to the vaccine that is used to this day. 

Plummer published or co-published more than 20 papers over a 25-year span, in respected publications such as the Canadian Journal of Microbiology, the Canadian Journal of Public Health, the American Journal of Public Health, and the British Journal of Experimental Pathology. She continued to research vaccines and treatments for various illnesses, including whooping cough and tuberculosis, until her retirement in 1959. 

Helen Plummer died Oct. 8, 1981 at the age of 85. She is buried in Greenwood Cemetery in Hartland, NB.

Find out more about the Connaught Laboratory 

• The Miracle Factory that began in a Stable — Maclean’s, Oct. 1, 1955
• A History of Connaught Laboratories