Fatou Diagne: A dream country and a daily difference

How Sanofi’s manufacturing and supply roles gave a Senegal-born engineer the chance to lead in Canada

Sanofi's Toronto site is growing. A new influenza facility recently opened there, a sign of investment and momentum building in the region. One of the people helping drive that work is Fatou Diagne, who has lived in four countries and now runs two of the site's vaccine buildings.

Fatou Diagne’s wish to help people began with her father, Modou, a biologist who worked extensively in healthcare in Senegal. “I grew up seeing him help people,” she recalls. Around her, others went without malaria medicine or lived with polio. “All of that could be prevented by a vaccine or a medicine.”

Fatou joined Sanofi in Toronto as a Deputy Director in April 2023 and is in her third role at the organization. As Director of Manufacturing, she now leads two buildings that make drug substance, the active ingredient of vaccines against pertussis (whooping cough), diphtheria and tetanus.

From quality assurance to a first leadership role

A career in medicine was the original plan, but engineering won out. Fatou left Senegal for France, where she studied biotechnology and then engineering. Quality assurance came next: the work was making sure that every operating document was clear, and that teams followed it.

At a previous role in biopharma, a colleague who knew of her interest in operations moved her into a quality role inside a manufacturing unit during a vaccination production ramp-up, from one batch a week to 3.5. “I wanted to be closer to the medicine,” she explains, “in the day-to-day manufacturing, just to make sure it was the right quality for the people who need it.”

Working in Canada had always been the dream. Fatou had shared her wish to live in an English-speaking country with her former colleagues, and one of them, Matthieu Puyet, who had since moved to Sanofi in Canada, helped bring her over. He is now Vice President, Industrial Operations and Site Head in France, and remains her mentor to this day

A little over a year after Fatou arrived, the leader of her production unit left, and she was asked to take over. Newly pregnant and unsure what the job would demand, Fatou applied anyway and told the hiring manager. By the time the appointment became official, she was around six months along.

“It made no difference to the person who was hiring,” Fatou says, “who still gave me the chance and the shot to handle this role, knowing it was my first time being a leader at this level.” Her predecessor, who had moved to the next building, and the hiring manager both guided her through a hard transition. “I wasn’t overly concerned,” she adds, “because I had people around me who were really helpful.”

Two buildings and more than a century of vaccines

Fatou’s scope has since widened from the building that makes the five pertussis antigens to a second, for diphtheria and tetanus. Staff call them the legacy buildings: a new building, B100, is meant to take over both products, after which the older plants will close. Until then, they run seven days a week, almost 24 hours a day, with some staff on nights and others starting very early. When Fatou ran only the pertussis building, its team numbered around 100.

Sanofi’s Toronto operation traces its roots to 1914, when the University of Toronto founded its Antitoxin Laboratories. In World War II, the laboratories developed combined antigens against diphtheria, pertussis and tetanus, and in the 1950s helped create the first effective polio vaccine. The site now makes vaccines for more than 60 countries, and in September 2026 opened an expansive new influenza vaccine facility, expected to start production in early 2027 and create career opportunities for those in the region.

What the work gives back

Operations is demanding, Fatou says, yet “one of the most rewarding jobs you can do, because of the people and the daily impact you feel you have on people’s health and lives.”

Fatou’s son, Idriss, has just turned two. “He’s very social. He loves people. He is a hugger,” she smiles. Motherhood has sharpened Fatou’s sense of purpose. The day Idris received one of Sanofi’s vaccines, made in Toronto, was “a great reminder” that her day-to-day work reaches her own baby. “

When Fatou called Modou with news of the job in Canada, he laughed, then said: “When you have something in mind, you never let go.” Fatou held on. The move, she says, was “a dream coming true.” Sometimes the most powerful career move starts with a dream you refuse to let go of.