The most valuable skill Thumbi Mwangi learned while pursuing his PhD in infectious disease epidemiology was "clarity of mind."

"The ability to distill the most critical things to focus on when you have a very complex situation to me was something I really envied and enjoyed seeing," said Thumbi, a co-director at the Center for Epidemiological Modeling and Analysis (CEMA) at the University of Nairobi and Associate Professor at the Paul G. Allen School for Global Health at Washington State University.

The skill served him well during the early chaos of the COVID-19 pandemic when there was a lot of noise and few answers. Thumbi was the first to model how long it would take for Kenya to reach its first 1,000 and 10,000 cases. Then he forecast how this trajectory could be flattened by minimizing people's contacts before COVID vaccines became available. He and his team became the go-to experts to inform the government's response to the pandemic.

Thumbi saw that Kenya didn't have enough data or data modelers to meet all the challenges posed by the pandemic. So, he and two other scientists he had been working closely with founded CEMA to build up the country's capacity to use data analytics and modeling to track the spread of diseases, identify potential outbreaks, and provide evidence-backed intervention strategies. Now, the government calls on CEMA to address a wide range of public health-related questions, from how to optimize the new national health insurance program to how to reduce the transmission, control and eliminate neglected diseases such as rabies.

That Thumbi became an infectious disease epidemiologist at all is the fortuitous result of following the advice - sometimes blindly - of trusted family members and mentors. When Thumbi was deciding what to study in college, his older brother, who was studying to become a surgeon, recommended veterinary school because an old school friend he had recently run into said he was enjoying it. After doing well on an exam during his first year in veterinary school, Professor Kiama Gitahi who later became his mentor, said to Thumbi: "By your 10^th year as a veterinarian you may be bored because a bone is a bone. It doesn't change. Consider becoming a researcher instead because then you will have so many problems to address in the world. You might enjoy it and keep your brain young."

Thumbi's father prodded him further. After graduating from veterinary school, Thumbi got a nice job in the pharmaceutical industry that came with a car, but his father said, "Go back to school and do more."

So Thumbi received a master's degree in genetics and animal breeding at the University of Nairobi, then a PhD from the University of Edinburgh in 2012. He began to understand what his Dad meant by "do more" while he was working on his PhD. Thumbi used models to study how multiple infections occurring in an individual at the same time or in sequence affected chances of survival and their growth performance; and how such disease events could be best controlled to protect and improve health in a population. He was developing skills that would come in handy during health emergencies as the pandemic, and that would remain relevant for controlling commonly occurring diseases.

Later, he shifted to investigating how zoonotic diseases like rabies move from animals to humans and modeling approaches to eliminating neglected tropical diseases in Africa. Then the pandemic hit.

He hopes that other CEMA-like chapters will open throughout Africa.

"I was told 25 years ago that I'll never get bored of research, and that turned out to be spot-on true," he said.