The history of Pfizer, the pharmaceutical giant which has achieved a coronavirus vaccine breakthrough, started with the treatment for another scourge of the time: parasitical worms.
Charles Pfizer, a migrant from Germany and trained chemist, founded the firm a year after his arrival in New York with cousin Charles Erhart, a confectioner, in 1849.
Their first development, an anti-parasitic called santonin, treated intestinal worms which were common in the United States at the time.
It went on to help the Union Army in the US as demands for painkillers and disinfectants grew during the Civil War.
Many decades later, Pfizer was the first company to mass produce penicillin. It is said most of the penicillin carried by soldiers on D-Day was developed by the company.
One of its most notable drugs, erectile dysfunction medication Viagra, was discovered in 1989 and approved in 1998, with its success leading Pfizer to seek to merge with a number of other pharma companies.