Editor’s note: This story was reported in collaboration with the Global Health Reporting Center with support from the Pulitzer Center.<\/p>\n
(CNN) \u2014\u00a0Vita Sara Blechner\u2019s life changed on a Saturday afternoon. The middle school librarian was home in Oceanside, New York, when she felt shooting pains in her back. After an acid reflux pill couldn\u2019t soothe the fiery feeling, her husband suggested a trip to the emergency room.<\/p>\n
It was March 7, 2020, just days before Covid-19 would turn New York City\u2019s hospitals into something approaching a war zone. If the doctors knew what was coming, they didn\u2019t let on. They were cool and collected as they put Blechner, then\u00a067, through a sonogram and a CT scan. But the pictures turned her world upside-down.<\/p>\n
\u201cThey said I have a tumor on my pancreas. And I said, \u2018No, it can\u2019t be. This can\u2019t be happening to me. I don\u2019t drink. I don\u2019t smoke. I\u2019m leading a healthy life.\u2019\u201d<\/p>\n
After an anxious two days in the hospital, Blechner headed home and weighed her options. There weren\u2019t many. Pancreatic cancer is notoriously unforgiving: Just 1 in 4 patients lives a year after their diagnosis. Just 1 in 10 makes it two years.<\/p>\n
Blechner felt the numbers in the pit of her stomach as she, her husband and their three adult sons made calls and pored over the internet, deciding her next move. They settled on a path that would land Blechner in a fast-moving and often misunderstood realm of cancer research.<\/p>\n
Messenger RNA, or mRNA, is a single-stranded molecule that delivers genetic information from DNA to direct the formation of proteins. It\u2019s known to most people from high school science classes or for its use in Covid vaccines. But long before anyone had heard of Covid, mRNA was generating intense excitement in the cancer research community. BioNTech, the German company that designed the Covid vaccine for Pfizer, adapted that vaccine from a platform it had been using to develop cancer treatments for nearly a decade.<\/p>\n
The mRNA-based Covid vaccines produced by Pfizer and Moderna helped blunt the impact of the pandemic but also sparked political backlash that, in the past year, has threatened to slow or derail dozens of potential cancer treatments. Now, after a tumultuous 12 months, there are signs that the mRNA train is still on track.<\/p>\n
\u201cIt\u2019s exciting,\u201d said Elizabeth Jaffee, deputy director of the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University. \u201cThere\u2019s been a number of successes in early-stage, positive trials.\u201d<\/p>\n
Dr. Catherine Wu, a professor of medicine at Dana Farber Cancer Institute and Harvard Medical School, says the recent stretch of positive real-world results helped drive the recent announcement by the National Cancer Institute that it would help raise $200 million specifically for novel cancer vaccines.<\/p>\n
\u201cWe\u2019re getting a lot of support from NCI in terms of developing and promoting cancer vaccines, and mRNA vaccines are a major part of that portfolio,\u201d she said.<\/p>\n
\t\t\t\t\t\t\tAn unforgiving enemy<\/p>\n
To guide her treatment, Blechner turned to doctors at Memorial Sloan Kettering Cancer Center, including Dr. Vinod Balachandran, director of MSK\u2019s Olayan Center for Cancer Vaccines.<\/p>\n
It\u2019s more challenging to make a vaccine against cancer than it is to create a vaccine against a virus or bacteria, Balachandran says. \u201cThat\u2019s because our body\u2019s immune systems are hard-wired to recognize viruses and pathogens as foreign, so a vaccine is teaching our body to do something it already wants to do. In contrast, cancer is ourselves. It\u2019s derived from our own tissues.\u201d<\/p>\n
Much of Balachandran\u2019s work the past two decades has focused on pancreatic tumors because the disease is such a tough nut to crack. \u201cIt\u2019s a cancer where nothing had really worked,\u201d he said.<\/p>\n
When Blechner arrived at MSK, he was just launching\u00a0a trial<\/a>\u00a0of an experimental mRNA-based vaccine against pancreatic cancer, in combination with standard immunotherapy and chemotherapy. He felt like a successful vaccine would also have the potential for wider application. \u201cIf we could break through and crack the toughest one, it could unlock how to crack the other [types of cancer], because it would provide a blueprint.\u201d<\/p>\n To develop the vaccine, he began by studying \u201csuper-survivors\u201d: the fewer than 10% of pancreatic cancer patients who live more than five years from the time of diagnosis. He found that their immune systems were especially good at spontaneously recognizing cancer cells as foreign. In fact, Balachandran says, these patients had about 12 times as many T-cells – a specialized type of immune cell – inside their tumors as average patients. The same T cells were circulating for more than a decade, in some cases.<\/p>\n Balachandran also realized that these weren\u2019t generic cancer-fighters. \u201cThese T cells were recognizing mutations,\u201d he said, \u201cbut each person\u2019s immune system was recognizing their cancer as foreign in a very specific way. To replicate this would require us to teach each individual person\u2019s immune system how to recognize their individual cancer. It would be an individualized vaccine. And we felt the best technology for rapid custom cancer vaccination was to use RNA.\u201d<\/p>\n \t\t\t\t\t\t\tTaking a chance as a research volunteer<\/p>\n After Blechner signed on for the trial, the first step was surgery. She underwent what\u2019s known as a Whipple procedure to remove the tumor in the head of her pancreas. In a lab at MSK, the tumor was preserved and sliced into fine pieces, each thinner than a human hair. In less than 72 hours, the package was en route to Germany, where technicians at BioNTech took steps to process the material into a clear liquid: a personalized vaccine, custom-made for Vita Sara Blechner.<\/p>\n A little more than two months after her diagnosis, the vaccine concoction from Germany arrived back in New York. By that time, she had been given a dose of an immune checkpoint inhibitor, an immunotherapy drug designed to make her immune cells more effective in fighting cancer. For weekly infusions of the vaccine, her husband, Simon, would drive Blechner from Oceanside to the MSK hospital on Manhattan\u2019s East Side. It was the height of the Covid pandemic, so instead of running errands or visiting friends after dropping her off, he would drive through empty streets and wait back home on Long Island. Blechner would lie in a hospital bed for eight hours while the vaccine coursed through her body, until Simon returned to pick her up.<\/p>\n After nine weeks, she was done and ready for the next step in her treatment: chemotherapy. But chemo was a fiasco. Blechner suffered mightily, with side effects so severe that doctors had to halt treatment. \u201cI got very sick,\u201d she recalled.<\/p>\n \u201cI only had three sessions before they had to stop, and I was in and out of the hospital three or four times. I was down to 90 pounds. I had no appetite. I was constantly nauseous, and my liver was damaged,\u201d she said. \u201cMy doctor said to me she never thought she\u2019d see me again.\u201d<\/p>\n By the time she felt strong enough to try again, her doctors felt it would be unsafe to resume. She hoped that stopping early wouldn\u2019t make a difference. But she would have to wait and see.<\/p>\n She tells this story more than six years later:\u00a0Blechner not only survived longer than anyone expected, she\u2019s still doing well and showing no sign of cancer.<\/p>\n And she\u2019s no singular exception. Of 16 patients in Balachandran\u2019s trial, eight showed a dramatic immune response to the mRNA-based vaccine. Seven of the eight are alive and well six years after the trial began, a finding that was to be presented Monday at the American Association of Cancer Research meeting in San Diego.<\/p>\n \u201cIt\u2019s exciting,\u201d Balachandran said. \u201cThe implication is that you can make a very strong immune response against the toughest of cancers, and it can last for this long. So if you could do it here, you could potentially do it in many other cancers.\u201d<\/p>\n Although a study with 16 patients is far from definitive, a larger multisite trial has been underway for a year.<\/p>\n The announcement comes on the heels of other encouraging news for pancreatic cancer patients. Earlier this month, the New York Times published an interview with former US Sen. Ben Sasse of Nebraska, who has been battling advanced pancreatic cancer and told the Times he\u2019s been taking an experimental drug that caused his tumors to shrink, albeit with some painful side effects. Last week, Revolution Medicines, the California-based biotech company running the phase 3 trial that Sasse is part of, said in\u00a0a news release<\/a>\u00a0that for patients whose cancer had spread, the drug nearly doubled survival time to 13.2 months, compared with 6.7 months among participants who didn\u2019t get the drug. Revolution also said it will seek approval from the US Food and Drug Administration for the drug, called daraxonrasib.<\/p>\n \t\t\t\t\t\t\tA promising technology under fire<\/p>\n Although much smaller than the Revolution study, the MSK trial stands as proof of concept for the promise of mRNA-based vaccines. The field has been a source of great excitement in recent years. But it also faced backlash in the wake of the pandemic and public concerns over Covid vaccines, even as most experts say major safety concerns around the latter are unfounded.<\/p>\n For cancer researchers, an early warning sign appeared in March 2025, when scientists reported that the acting director of the National Institutes of Health, Dr. Matthew Memoli, had sent a letter asking that all grants, collaborations or contracts involving mRNA be flagged.<\/p>\n For some, the low point came in May, when the White House proposed an unprecedented cut of more than 40% to funding for the National Cancer Institute. Twenty-six days later, in an apparently unrelated move, the US Department of Health and Human Services canceled a $590 million deal with Moderna to develop an mRNA-based vaccine against emerging pandemic influenza. In August, HHS followed up by announcing it would no longer fund mRNA research through the Biomedical Advanced Research and Development Authority. The latter move involved the cancellation of 22 separate contracts.<\/p>\n More recently, the FDA canceled its review of Moderna\u2019s mRNA-based flu vaccine, while criticizing the design of the company\u2019s clinical trial, but the agency reversed its decision a week later after fierce criticism.<\/p>\n FDA Commissioner Dr. Marty Makary has said the agency bears no animus toward mRNA and that it terminated contracts last year solely to save taxpayer money. \u201cThe companies that made mRNA vaccines made over $50 billion. They can fund their own research,\u201d Makary said at a news conference in February.<\/p>\n Still, many researchers who once saw a bright future felt their faith shaken. \u201cThe external threats are real,\u201d Wu said. \u201cIt forced us to really step back and think. I wouldn\u2019t be genuine if I said we weren\u2019t all concerned.\u201d<\/p>\n Dr. Ryan Sullivan, director of the Center for Melanoma at Mass General Brigham Cancer Institute, says mistrust of mRNA vaccines since the pandemic has at times made it harder to recruit people into his clinical trials.<\/p>\n \u201cMost people don\u2019t have significant concerns, but some are reluctant,\u201d Sullivan said. \u201cThe skepticism over vaccines in general is a little bit lessened around cancer vaccines, but not totally, and some people are resistant to the concept, even when they\u2019re fighting cancer.\u201d<\/p>\n \t\t\t\t\t\t\tOne technology, many paths<\/p>\n Sullivan is an investigator on multiple studies with mRNA vaccines, including a large-scale trial run by drugmakers Moderna and Merck, testing an mRNA-based therapy in combination with Keytruda, an immunotherapy drug, as a treatment for melanoma. In January, the companies\u00a0announced<\/a>\u00a0that the combination cut the death rate for participants in their study by 49% over five years. A larger phase 3 trial is underway, and the companies are also testing the therapy against non-small cell lung cancer, bladder cancer and renal cell carcinoma.<\/p>\n Like the vaccine that helped Blechner, Merck and Moderna\u2019s melanoma treatment is personalized, meaning an individual patient\u2019s tumor cells are used to engineer a highly specific immune response. Another approach involves what are called generalized or off-the-shelf vaccines, that are not tailored to each individual patient. BioNTech and the Moderna\/Merck collaboration are both working on approaches that use mRNA to encode and deliver a predefined set of antigens – immune targets – that are typically shared across patients with a given tumor type in hopes of stimulating the immune system into a more aggressive response.<\/p>\n Dr. Elias Sayour, a pediatric oncologist and researcher at the University of Florida, has gone a step further in the \u201cgeneric\u201d direction, testing mRNA vaccines that don\u2019t code for any specific antigen at all. In\u00a0a study<\/a>\u00a0published last year in the journal Nature Biomedical Engineering, Sayour treated mice with a generalized vaccine, using mRNA to stimulate production of a protein called PD-L1, making their tumors more susceptible to immunotherapy. It worked.<\/p>\n \u201cWe\u2019ve discovered that mRNA doesn\u2019t need to be specific, to reprogram the immune response,\u201d Sayour said.<\/p>\n \u201cWe\u2019re trying to create a new paradigm,\u201d he added. \u201cIt takes weeks to create a personalized vaccine. The idea of universalization is to wake up the immune system more rapidly.\u201d<\/p>\n He says the two approaches could, in theory, complement each other: A newly diagnosed patient might receive an off-the-shelf vaccine to ramp up their immune system and a personalized vaccine later in their course of treatment.<\/p>\n