Who is Drew Weissman
Drew Weissman is an American physician and immunologist born in Lexington, Massachusetts, on 7 September 1959. He shared the 2023 Nobel Prize in Physiology or Medicine with Katalin Karikó for discoveries concerning RNA modifications that enabled effective mRNA vaccines against COVID-19.[6]
Medical and scientific education
While at school he worked at his father’s company, which manufactured optical mirrors for satellites, alongside an early interest in science and technology.[7] He received bachelor’s and master’s degrees from Brandeis in 1981, studying biochemistry and enzymology.[9]
He completed his MD and PhD at Boston University in 1987. After residency in Boston, he conducted research at the National Institutes of Health with Anthony Fauci.[8] He joined the University of Pennsylvania in 1997, establishing his immunology and vaccine research programme.[9]
HIV and dendritic cells
Before focusing on mRNA, he studied HIV interactions with immune cells. In 1995 he published work with Li, Orenstein and Fauci showing that different dendritic-cell populations could bind HIV but differed in transmitting infection to T cells. The distinction connected cell maturation with viral propagation.[10]
Collaboration with Karikó
In the late 1990s he met Karikó beside a Penn photocopier. A research conversation began a collaboration between immunology and RNA biochemistry.[8] Both were among the authors of the 2005 study on modified nucleosides and immune recognition.[6]
The work continued after the initial discovery. In 2008, Karikó, Muramatsu, Welsh, Ludwig, Kato, Akira and Weissman demonstrated advantages of incorporating pseudouridine into mRNA. Experiments linked the modification with greater protein production and biological stability, expanding its potential as an expression vehicle.[11]
In 2011 they examined another obstacle: double-stranded RNA contaminants generated during transcription. Chromatographic purification reduced immune activation and improved modified-RNA expression. The paper, by Karikó, Muramatsu, Ludwig and Weissman, showed that preparation composition and purity also influenced performance.[12]
RNA and lipid nanoparticles
mRNA formulations require systems that protect the molecule and deliver it to cells. The 2022 Tang Prize jointly recognised Weissman, Karikó and Pieter Cullis, linking modified RNA with lipid nanoparticles. This combination brought together RNA chemistry, immunology and pharmaceutical delivery systems.[21]
Vaccine research beyond COVID-19
In 2017 he contributed to Pardi and colleagues’ study of an experimental mRNA Zika vaccine. Researchers observed antibody responses and protection in mice and rhesus macaques. Predating the pandemic, the work explored adapting the platform to another virus in animal models.[13]
Arevalo and colleagues’ 2022 study combined antigens from twenty known influenza A and B subtypes and tested them in mice and ferrets. Weissman supervised mRNA–nanoparticle production; Scott Hensley supervised the other activities. This was preclinical research on breadth of protection, rather than an approved universal vaccine.[14]
Cell reprogramming and new therapies
A Penn study published in 2022 used mRNA to generate temporary CAR T cells inside the body. In mice, the aim was targeting fibroblasts associated with cardiac fibrosis. Weissman coauthored the research, which sought to simplify a strategy usually involving cell modification outside the body.[15]
In 2023 he contributed to Breda and colleagues’ study of mRNA delivery to haematopoietic stem cells. It included cell modification in mice and experiments involving human sickle-cell-disease cells. The work explored editing and transplant-preparation approaches within specific experimental systems.[16]
In 2022 he was among the founding scientists associated with the launch of Capstan Therapeutics. The project brought together Penn specialists in immunotherapy, RNA and nanoparticles targeting particular cell types. It was established to develop applications of the research, drawing on several scientific contributions within its founding team.[19]
Thailand collaboration and access
In 2020 he began collaborating with Kiat Ruxrungtham and Chulalongkorn University on a Thai mRNA vaccine. Penn documented meetings, data review, and production and testing assistance without compensation for that support. The programme sought to expand development capacity in countries with fewer resources.[17]
Phase I ChulaCov19 results appeared in 2022. The open-label trial included 72 people aged 18–75 and evaluated safety and immunogenicity. Its observations informed continued development; this early design did not measure population-level vaccination effectiveness.[18]
Nobel Prize and scientific recognition
Brandeis held the Rosenstiel Award ceremony for Weissman and Karikó in February 2021.[23] They shared that year’s Lasker–DeBakey Clinical Medical Research Award.[22] Weissman is also a 2022 Breakthrough Prize in Life Sciences laureate for modified-RNA technology.[20]
He entered the National Inventors Hall of Fame in 2023, whose profile highlights US patent 8,278,036.[7]
Scientific leadership and perspective
He directs the Penn Institute for RNA Innovation, combining basic research on RNA and immune responses with vaccine development and other therapeutic applications.[1] Penn also describes international collaboration to train researchers and develop local manufacturing capacity. Technology access forms part of that institutional programme.[24]
In a 2024 interview he explained how investigating failed experiments helped guide subsequent hypotheses. He also expressly acknowledged the importance of Cullis’s nanoparticles. His account presents innovation as accumulated knowledge and collaboration, bringing together delivery, immune-response and manufacturing problems.[2]
mRNA vaccines and exposure in essential occupations
Weissman and Karikó’s work on RNA modifications contributed to the development of mRNA vaccines against COVID-19, as recognised by the Nobel Prize.[3] The HEROES and RECOVER cohorts evaluated these vaccines among US healthcare personnel, first responders and other essential workers, with follow-up from December 2020 to March 2021.[5]
The study used weekly testing regardless of symptoms.[5]
This feature helps explain preventive evaluation: recording only sickness absence or clinical consultations would have answered a different question from detecting infections throughout follow-up. The case enables examination of the population studied, the outcome measured and the observation period, instead of treating “effective” as a context-free description. These historical findings are not a current protection estimate and do not establish that vaccination removes the exposures present in a job.
