It was 4:00 in the morning when Katalin Karikó H’23 received the call that she and Drew Weissman ’81 GSAS MA ’81 P ’15 H ’23 had been awarded the Nobel Prize for their seminal messenger RNA research, which ultimately led to the expedited development of COVID-19 vaccines and the prevention of millions of deaths worldwide.

“We don’t have a good number for Drew,” Thomas Perlmann, the Nobel Assembly Secretary, told Karikó. “We tried to call him and couldn’t reach him.”

“Originally we thought it was a joke — that somebody was playing a prank on us and we really didn’t win the Nobel Prize,” Weissman said in an Oct. 6 interview with the Justice. “I didn’t hear anything until around 5:20 in the morning when they called me and said, ‘You and Kati won the Nobel Prize.’ I still waited for the announcement on their website before I fully believed it.”

25 years ago when Weissman and Karikó first met at a photocopier at the University of Pennsylvania, they could have never anticipated that their research would be pivotal in the battle against one of the deadliest pandemics in human history. 

Weissman, who completed his allergy and immunology fellowship at the National Institutes of Health in the lab of Dr. Anthony Fauci, was studying new approaches to an HIV vaccine when he met Karikó. Weissman explained how he started a new project at UPenn developing HIV vaccines using dendritic cells and loading them with antigens, DNA peptides, viruses, and proteins. “I had everything but the mRNA,” he said. “That’s when I met Kati at the Xerox machine and she told me she makes mRNA so we started working together.”

Once Karikó made the mRNA, Weissman would check if it was immunogenic or not by injecting the mRNA into cells to elicit an immune response. However, the mRNA was incredibly inflammatory, which is part of the immune response that they wanted to limit as much as possible because the cells would immediately destroy the injected mRNA. Years later, they discovered that encapsulating the mRNA in a particular lipid curbed inflammation and enabled the mRNA to be taken up by the cells with a suppressed inflammatory response. 

With this new innovation, Karikó and Weissman opened a new realm of possibilities for vaccine development. Weissman explained in an interview with The New York Times that initially other scientists were not interested in the new approach to vaccination. While mRNA vaccines use synthetic mRNA to teach cells how to make a protein that triggers an immune response within the body, traditional vaccines inject an inactive or weakened virus into the body to trigger an immune response.

In 2005, Karikó and Weissman’s paper was finally published by Immunity after being rejected by the more well-known scientific journals Nature and Science. 

Before the COVID-19 pandemic emerged, Weissman and Karikó were working with Moderna and BioNTech on five Phase I clinical trials of vaccines, including one for the Influenza virus, but the majority of the public did not know about it. Although the other vaccines were stuck in clinical trials for a while, Karikó and Weissman’s work came together rapidly to fight the spread of COVID-19. “We’ve been ready for a pandemic for years,” Weissman told the Justice.

“We made an mRNA that encoded the spiked antigen,” he explained. “We put it into LLPS and started immunizing animals. Moderna and [Pfizer-]BioNTech did the same thing. They actually went straight to people … before they did animal studies. That’s why the first people were immunized two months after the sequence was released. They went as fast as they possibly could to get the [COVID-19] vaccine made and approved quickly.” Weissman clarified that the animal trials were safe.

The NIH found that mRNA vaccines were more effective in producing antibodies to fight COVID-19 than the inactive virus vaccine. 

In the United States alone, medical centers have administered 400 million doses of the Pfizer-BioNTech vaccine and 250 million doses of the Moderna vaccine. Globally, pharmaceuticals have administered hundreds of millions more, with mRNA vaccines enabling updated boosters to protect people from new variants. 

“The human data, which is most important, showed that within a couple weeks after the first immunization people started to see protection [from the virus],” said Weissman. “It was 60-70% that came up — as I remember — around two weeks after the first vaccine. After the second vaccine was five to seven days when the antibodies were boosted. And people got 95% protection.” He explained that it is natural for the response to the primary vaccine to be slower than for a booster vaccine. 

The mRNA vaccine has completely innovated vaccine technology, paving the way to one day equip immune systems against many other fatal diseases such as cancer, malaria, sickle cell anemia, leptospirosis, and even peanut allergies. 

Weissman explained that winning the Nobel has not changed his perception of his responsibilities as a global citizen. “Once we made the mRNA vaccine, that was my role already. I travel the world talking to young people to encourage them to go into science and talking to scientists around the world to help them develop vaccines.”

Weissman and Karikó have worked with the World Health Organization to build 15 good manufacturing practice sites across sub-Saharan Africa, South America, and Eastern Europe. “GMP is the grade of production you need for vaccines and drugs,” explained Weissman. “We actually have one being built in Ukraine right now during the war,” he added. 

“The hope is that as [the sites] come online, they’ll give local regions access to the GMP drug.” In addition to helping researchers develop new vaccines, these sites enable lower and middle class countries to rapidly make and distribute vaccines if another pandemic hits. Large pharmaceuticals do not have an interest in making vaccines for dengue or tularemia because they will lose money by only selling vaccines to poor countries, Weissman explained, but these sites empower those countries with the resources for vaccine research and development.  

Last May Weissman delivered the commencement address in which he explained how it was during his years at Brandeis that he realized the importance of applying social justice to his scientific research. 

“We’ve got malaria vaccines in clinical trials,” Weissman told the Justice. “Moderna has a dengue vaccine in clinical trials. We’re collaborating with researchers in Brazil who are making Zika mRNA vaccine. We have vaccines for C. difficile infection. We’ve got vaccines for miragic fever viruses, for herpes viruses. The scope is enormous. We also have vaccines for autoimmune diseases and for food allergies and aeroallergen allergies.”

When asked if those vaccines will also require multiple doses, Weissman said that it is still unknown. “My assumption is that there will be one vaccine for malaria, but you might need to get boosters every five to ten to 20 years — and probably similar for dengue. We get the tetanus [shot] every 10 years; we get our MMR boosted every so often. Vaccines require boosters.”

Brandeis is also where Weissman got his start in scientific research, receiving both a BA and MA in biochemistry and enzymology in 1981 — at only 22 years old — while working in the lab of Prof. Gerry Fasman (BCHM). Weissman recalled being excited at the prospect of working with Fasman’s minicomputer. “Minicomputers were just being released at the time. He did such high dimension calculations with it,” said Weissman. “Gerry was a great mentor, and I still have a lot of friends from the lab.”

During his commencement speech, Weissman fondly recalled some of the long-lasting bonds he made at Brandeis, including meeting his wife Mary Ellen Weissman. “It was here where I met my wife, now a gifted child psychologist, while tutoring her in calculus,” he said to the audience. “Although I’ll admit the only thing she seems to remember from those sessions is that I explained the concept of infinity by comparing it to her boundless desire for shoes.”

The Justice asked Weissman what funny moments stand out from his years at Brandeis. “Most of those moments I can’t share with you for a variety of reasons,” he joked. “There was one day — I forgot the name it was called — but it was named after a professor who used to smoke pot with all the students. And we had a day — Brandeis had gotten rid of it since the 80’s — where the student activity group could buy a ton of pot and roll it into joints and pass the joints out to everybody on campus. That was always an interesting day. I didn’t smoke, but it was fun just watching people … I don’t know how they got rid of [that tradition]. If you want to bring it back, you have my support.”

Weissman also offered some genuine advice to Brandeis students: “I think the most important thing is to find a career or a future in something you love … Your time at Brandeis, you’re exposed to lots of different things to help you decide what kind of careers and what kind of futures you want. I would take advantage of as many of those as possible.”

A heart-warming video circulating YouTube captures the special moment when Weissman told his 90-year-old mother and 91-year-old father that he won the Nobel. His mother said to him, “You’re the product of our hearts, Drew.”

In 2021, Brandeis awarded Weissman and Karikó with the 50th Annual Lewis S. Rosenstiel Award in basic medical research and the Lasker Award in clinical medical research. At the Class of 2023 graduation ceremony, the University also awarded Weissman and Karikó with Honorary Doctorates of Science.  

 — Editor’s Note: Justice Editor Sophia De Lisi contributed to the reporting of this article.