Michael Yeadon was a scientific researcher

Late last year, a semi-retired British scientist co-authored a petition to Europe’s medicines regulator. The petitioners made a bold demand: Halt COVID-19 vaccine clinical trials.

Even bolder was their argument for doing so: They speculated, without providing evidence, that the vaccines could cause infertility in women.

The document appeared on a German website on Dec.1. Scientists denounced the theory. Regulators weren’t swayed, either: Weeks later, the European Medicines Agency approved the European Union’s first COVID-19 shot, co-developed by Pfizer Inc. But damage was already done.

Social media quickly spread exaggerated claims that COVID-19 jabs cause female infertility. Within weeks, doctors and nurses in Britain began reporting that concerned women were asking them whether it was true, according to the Royal College of Obstetricians & Gynaecologists. In January, a survey by the Kaiser Family Foundation (KFF), a non-profit organization, found that 13% of unvaccinated people in the United States had heard that “COVID-19 vaccines have been shown to cause infertility.”

What gave the debunked claim credibility was that one of the petition’s co-authors, Michael Yeadon, wasn’t just any scientist. The 60-year-old is a former vice president of Pfizer, where he spent 16 years as an allergy and respiratory researcher. He later co-founded a biotech firm that the Swiss drugmaker Novartis purchased for at least $325 million.