Scientists Katalin Karikó and Drew Weissman were jointly awarded the Nobel Prize in “Physiology or Medicine” on Monday, Oct. 2 for their chemical modifications of mRNA that allowed effective COVID-19 vaccines to be produced.

 In less than one year, their findings enabled the production of vaccines that averted millions of deaths and globally assisted in pulling society out of its most major pandemic in over a century.

In 2005, the two made a key breakthrough in the medical field: they discovered that mRNA could be altered and distributed throughout the body to activate the immune system. These vaccines demonstrated an enormous immune response, stimulating the production of antibodies that could combat infectious diseases never previously encountered.

Karikó and Weissman’s research laid the foundation for vaccines that could one day be used to fight against fatal diseases such as cancer.Karikó is now the 13th woman out of 227 individuals to win the Nobel Prize in Physiology or Medicine since 1901. Together, Karikó and Weissman are the 28th and 29th Nobel laureates affiliated with the University of Pennsylvania, where the two worked as professors and conducted the majority of their research.