Timothy Springer thought his fortune was excessive, even before he became a billionaire.

“I’ve had more than enough wealth for myself for some time,” Springer said in a 2018 interview. “I don’t feel I need more.”

The Harvard University medical professor’s riches are much bigger now, thanks to his stake in Moderna Inc., the U.S. biotechnology firm attempting to develop a vaccine for the novel coronavirus.

Shares in the Cambridge, Massachusetts-based company (MRNA) surged 162% this year through Wednesday, boosting Springer’s net worth to more than $1 billion, according to the Bloomberg Billionaires Index.

Springer, 72, is among those whose wealth has increased during the coronavirus pandemic. Another is Zoom Video Communications Inc. founder Eric Yuan, whose net worth has more than doubled this year as demand for its teleconferencing service exploded.

Springer didn’t respond to requests for comment, while a Moderna spokeswoman declined to comment.

Moderna’s mRNA-1273 vaccine is one of the first to begin human trials. The U.S. Department of Health and Human Services agreed last week to pay more than $400 million for the company to develop the product, which could reach final-stage testing this year if the trial succeeds. There are about 70 vaccines in various stages of development, the World Health Organization said.

Springer is one of the wealthiest academics in the U.S., having made about $100 million when his first venture was bought by Millennium Pharmaceuticals in 1999. He invested $5 million in Moderna, which went public in 2018, and that stake is now worth more than $800 million.

“I have an academic lifestyle,” Springer said in the 2018 interview. “I’m not into ramen noodles, but my friends are academics, so it doesn’t really behoove me to be flashy.”