Tanja Stadler

Tanja Stadler, Full Professor at the Department of Biosystems Science and Engineering of ETH Zurich, was one of the key scientific figures in Switzerland during the pandemic. Within the Covid-19 Science Task Force set up to advise the authorities, Stadler led the panel of experts entrusted with calculating the all-important R number, which indicates whether the pandemic is growing or receding. The Swiss government used the R-number and other data to determine its anti-Covid strategy – a big responsibility for the mathematician, not least after she became chair of the task force in summer 2021. She was 40 at the time and one of the youngest on the committee.

“This lady’s numbers determine our freedom” was the headline in one newspaper. Stadler herself is not one for hype. In the public crossfire, the multi-award-winning academic stuck soberly to facts and evidence. Nevertheless, like other scientists who appeared in public during the pandemic, she found herself the target of hatred and threats. However, she never fell into the trap of saying anything political. She always emphasised that she was just explaining the science, and it was up to the politicians to decide what to do. Any signals she may have given were subtle – for example when she appeared for a television interview still wearing a protective mask after the early lifting of restrictions in Switzerland. The task force disbanded at the end of March, but Tanja Stadler continues to study how viruses spread and change. Even as a child, she was interested in scientific phenomena. She has now become an inspiration for other young women aspiring to break into areas of science that used to be dominated by men.