Health
Weissman was jointly awarded the 2023 Nobel Prize in Medicine with Katalin Karikó for discoveries which made COVID-19 vaccines possible.
Drew Weissman's mRNA research with Katalin Karikó was crucial to the development of COVID-19 vaccines.
Drew Weissman's mRNA research with Katalin Karikó was crucial to the development of COVID-19 vaccines. Peggy Peterson/AP
By Darin Zullo
March 24, 2025 | 7:58 PM
4 minutes to read
Five years after the COVID-19 pandemic shut down the world, Dr. Drew Weissman’s contributions to the development of the vaccines remain monumental.
Weissman’s medical study brought him to the Boston area. He earned a bachelor’s and master’s degrees from Brandeis University and an MD and PhD from Boston University. After a residency at Beth Israel Hospital, he studied HIV at the National Institutes of Health (NIH).
In 1997, Weissman arrived at Penn Medicine and met Dr. Katalin (Kati) Karikó, with whom he would later share a Nobel Prize. Eight years of research led them to their discovery that messenger RNA (mRNA) could be modified and delivered in fat droplets called lipid nanoparticles, enabling it to trigger the immune system to fight disease.
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More than a decade later, these breakthroughs proved crucial to using mRNA in COVID vaccines. In 2023, Weissman and Karikó were jointly awarded the Nobel Prize in Medicine.
As the pandemic’s impact lingers, Weissman and his team are working to develop several more vaccines, including a pan-coronavirus vaccine, a universal flu vaccine, and a herpes vaccine. Boston.com sat down with Weissman for a Q&A about vaccine development, vaccine hesitancy, governmental involvement, and the prospect of another pandemic.
The following interview has been edited for clarity and length.
How did you begin at Penn Medicine?
I came here from the NIH, where I was an HIV dendritic cell researcher in Tony Fauci’s lab. I had been there for seven years, and I came to Penn and started my own lab, and that’s when I met Kati Karikó. Kati had been working on RNA for around 10 years and wasn’t getting very far with it. We met at the photocopier and started talking and working together, and that led us to here.
Could you tell me about your 2005 discoveries that ultimately lead to you winning the Nobel Prize?
That was the culmination of about eight years of work that Kati and I did, and we first noticed that RNA was very inflammatory, and that was unexpected at the time. We tried to figure out why it was so inflammatory, and that led us to study modified nucleosides. The 2005 paper is demonstrating that if you put modified nucleosides in the RNA, it loses a lot of its inflammatory activity.
How did those discoveries pave the way for the COVID-19 vaccines?
That was the first step to show we could get rid of inflammation. A couple years after that, we showed that the modified RNA was translated much better than unmodified. So, in the mid 1990s, drug companies, biotech companies, did clinical trials that didn’t work using RNA and gave up. [They] said “it’s too inflammatory, it doesn’t make enough protein, it’s too hard to work with,” and they stopped using it. We got rid of the inflammation, and we increased the amount of protein the RNA made by 10,000 fold.
Three years after the pandemic began, you won the Nobel Prize in Medicine with Dr. Karikó. What was your reaction to that?
Penn had been warning us for every year after the vaccine was released, and they were actually sending photographers wherever we went, just in case we won. I got a text from Kati at 4 in the morning. Usually they call at 6:30 for the East Coast, but they called Kati earlier and said, “You and Drew won.” I didn’t believe it when Kati first called, or when they first called, because we have a lot of problems with anti-vaxxers and crazy people attacking us, threatening us, and I thought they were playing a joke.
In the wake of the pandemic and amid a surge in anti-vaccine activism, what are your thoughts on that resistance to vaccines?
The resistance has been around since vaccines were invented back in 1796 when [Edward] Jenner first made a cow pox vaccine. What surprised me about the current anti-vaxxers is that they’re based in our government, and they’re promoted by our government. I always thought the job of the government was to help people and to make them healthier, and now we’ve got a significant portion of our government who is trying to cancel vaccines, and is turning against science, and I had never seen that before. That’s a very upsetting part of all of this.
Given the recent funding cuts at the NIH and Robert F. Kennedy Jr. entering the scene at the HHS, do you feel like we’re unprepared for another pandemic?
The fear is that the NIH and RFK are going to cancel all RNA vaccines. There’s a huge platform of new drugs, new therapeutics that are being developed that could potentially be stopped. That’s going to lead to more deaths, worsening health, and what the conservatives should care about, it’s going to lead to China and other countries being the leaders in these fields instead of the US.
What else should the general public know about the viability and safety of vaccines?
Studies have been done on who’s responsible for the anti-vaccine misinformation, and what they found is that the majority of the biggest anti-vax people are split between lawyers who sue vaccine companies for made-up autism or made-up adverse events to make money, or they’re physicians who invent osteopathic, worthless treatments. RFK Jr. used to be a lawyer that worked for a company that sued drug companies because of made-up vaccine ailments. People don’t believe this or don’t understand this. They think, ‘oh, well, these people are on my side,’ and they’re on the internet telling me to be careful. And they believe it.
How are vaccine researchers preparing for another pandemic?
So, there’s two ways to prepare. The first is to establish testing and protection, PPEs, masks, gloves, the ability to quickly make testing equipment. The second is to make vaccines. Often, we don’t know what the next pandemic is going to be. We know influenza gives us a pandemic every once in a while, so what we’ve been doing is making pan vaccines, or universal vaccines, that work against all coronaviruses and all influenza viruses. That way, you’ve got a vaccine that’s ready to go the minute cases start appearing, and you don’t have to spend 10 months making a brand new vaccine.
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There’s not much the public can do to physically prevent a pandemic, but they should be talking with their legislators about making sure the government and NIH researchers are funded and prepared for the next pandemic.
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