Chase Johnson’s cancer was found by a dog. Not by a scan, not by a routine exam, but by Cato, her devoted dog, who kept nudging her chest with his nose until she finally felt the lump. She was 31, living in Cary, North Carolina, nearly a decade younger than the recommended age for regular mammograms, and she had no family history of breast cancer. The diagnosis was stage 2B triple-negative breast cancer, a rare and aggressive form of the disease. Treatment was brutal: chemotherapy, radiation, surgery. In 2022, doctors declared her cancer-free, but her oncologist immediately warned her that there was a 40 percent chance the cancer would return. For Johnson, the word “remission” did not feel like an ending. It felt like waiting for the next shoe to drop. When she heard about a clinical trial at the Cleveland Clinic testing a vaccine designed to teach the immune system to recognize and destroy any returning cancer cells, she signed up. The vaccine, developed in partnership with Anixa Biosciences, had already generated an immune response in nearly three-quarters of the participants. Johnson was one of them. At 31, she had been too young for a mammogram by medical guidelines, and there had been no obvious reason to be checked. The fact that a dog’s persistent nudge led her to seek help felt almost miraculous. But miracles are not guaranteed. Her doctors were hopeful, yet guarded. The clinical trial was not presented as a cure. It was presented as a possibility, a chance to tilt the odds. “It’s just so promising and as a patient, it gave me a lot of hope,” she said. Now 37 and five years in remission, she celebrated a milestone this summer. She still lives with a low hum of anxiety, a background noise left by cancer. But she says it is quieter now. “I feel much more protected having done it,” she explained. “It’s given me a great, great amount of peace of mind.” Her story captures the emotional reality behind the headlines about cancer vaccines. These are not abstract molecules. They are hopes grafted onto the body after trauma, small shields carried against the dark.
Cancer vaccines are not science fiction. For more than two decades, researchers have made steady progress in developing them. Johnson’s vaccine is not an mRNA vaccine, but scientists are especially excited about mRNA technology, which uses synthetic genetic instructions to turn the body into a kind of living pharmacy. Here is how it works: cancer cells are not complete strangers. They are normal cells that have mutated, and they display abnormal proteins on their surfaces. An mRNA vaccine carries the instructions for one of those proteins into the body, teaching immune cells to recognize it as a threat and destroy any cell that carries it. Some cancer vaccines are preventive, like the HPV vaccine, which protects against viruses that cause cancer. Others are therapeutic, meant to treat existing cancer or prevent recurrence after treatment. The field is moving quickly. Recently, pharmaceutical companies Moderna and Merck announced that a personalized mRNA cancer vaccine, combined with an immunotherapy drug, had succeeded in a late-stage trial for skin cancer. Each vaccine was customized to the unique mutations of a patient’s tumor. The news raised hopes that a wave of new cancer vaccines could be just over the horizon. For millions of people who have watched loved ones suffer through chemotherapy and radiation, this is genuinely thrilling. A vaccine that could train your own body to guard against the return of cancer feels almost like a miracle. But the same researchers who are celebrating this progress also have a knot in their stomachs. They know that a vaccine only works if people are willing to take it. And they are watching misinformation spread faster than the science.
Many doctors and researchers fear that the politicization of vaccines during the COVID-19 pandemic has done lasting damage. They point to a particularly dangerous false claim: that mRNA vaccines can “super-charge” tumors, creating what conspiracy theorists call “turbo cancer.” There is no evidence for this. The National Cancer Institute has stated clearly that there is no evidence COVID-19 vaccines cause cancer. Yet the lie persists, amplified in some cases by people in power. Robert F. Kennedy Jr., now the secretary of the Department of Health and Human Services, has helped amplify vaccine misinformation for years. Researchers worry that the same falsehoods will be recycled and aimed at new cancer vaccines, scaring away exactly the patients who need them most. The concern is not hypothetical. The United States has already seen what happens when a vaccine that prevents cancer meets a wave of misinformation. The human papillomavirus, or HPV, is a sexually transmitted infection, and certain strains can cause cancers of the cervix, vagina, vulva, penis, anus, mouth, throat, head and neck. The HPV vaccine was approved in 2006 for girls and women ages 9 to 26, and three years later approval was expanded to boys and young men. It is most effective when given before a person becomes sexually active. It is safe. It is extremely effective. It is one of the few vaccines that actually prevents cancer. Yet decades of misinformation, some of it spread by state and federal lawmakers, have kept vaccination rates stuck. For four years in a row, teen HPV vaccination rates have not budged. The resistance has always been cultural as well as scientific. Some conservative lawmakers and parents associated the vaccine with teen sex and used that discomfort to justify avoidance. The result is a generation of adults at higher risk for preventable cancers.
Dannell Boatman, an assistant professor at the West Virginia University Cancer Institute, co-authored a 2024 study funded by Merck that looked at HPV misinformation on social media. The most pervasive misinformation appeared in user comments. “There were some really wild conspiracy theories about girls in India being killed with the HPV vaccine,” Boatman said. “We also were able to identify a lot of mistrust of authority.” She expects a similar dynamic around breast cancer vaccines, especially because false claims already circulate that mammograms can cause cancer. She is studying a strategy called “inoculation theory,” which involves forewarning people that they will be exposed to misinformation and giving them a small dose of evidence to resist it. It is an attempt to build immunity against lies. But the challenge is enormous. The people now in charge of American public health have not been neutral observers in this fight. Before joining the Trump administration, Kennedy filed complaints and lawsuits against Merck, the maker of the HPV vaccine. He claimed on social media that the vaccine appeared to be increasing the risk of cervical cancer, a statement that contradicts all available evidence. After becoming HHS secretary, he dismissed all 17 members of the agency’s vaccine advisory panel and replaced some of them with vaccine skeptics. His department altered the official child vaccine schedule for certain diseases, including HPV; federal courts have blocked those changes. Last month, President Donald Trump signed an executive order directing that the combined measles, mumps and rubella vaccine be split into separate shots, and then falsely suggested that each individual vaccine could fill a “bottle of soda.” The administration has also proposed cutting funding for vaccine research and for studies on vaccine hesitancy.
For public health officials, the effect has been disorienting. Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, said Kennedy’s appointment spurred the creation of the Vaccine Integrity Project, a partnership with the American Medical Association aimed at rebuilding public trust in vaccines. The project has published evidence reviews defending vaccines that the administration has attacked. In May, it found that HPV vaccines are not associated with serious side effects and reduce the risk of cervical cancer by 80 percent in people vaccinated by age 16, and by 66 percent in those vaccinated later. “To a young parent today who wants to do the right thing, they want to protect their child, they’re so confused because they hear from the leaders in public health in their government talk about these vaccines killing people,” Osterholm said. “The credibility of 80 years of public health work of vaccines in this country is threatened because of confusion.” State lawmakers have played a major role too. Last year, 78 percent of U.S. teenagers ages 13 to 17 had received at least one dose of the HPV vaccine, and 63 percent had completed the full series. But in conservative-leaning states, the numbers are much lower. The complete vaccination rate was only 31 percent in Mississippi, 46 percent in Oklahoma, 50 percent in Kentucky, 52 percent in Arkansas and 55 percent in South Carolina. At the other end of the spectrum were Rhode Island, Hawaii and Massachusetts, all above 80 percent. Some states, including Alabama and Oregon, have made recent efforts to boost HPV vaccination rates. But others are moving in the opposite direction. Iowa’s Republican governor, Kim Reynolds, signed a law in May prohibiting anyone under 18 from consenting to vaccinations related to sexually transmitted diseases, including HPV. This year, lawmakers in 34 states introduced 209 bills designed to loosen vaccination rules, limit access to certain vaccines, or spread doubt about their safety. In Idaho, Republicans introduced a bill that would have imposed a two-year moratorium on mRNA immunizations for children and pregnant women. Similar bills appeared in at least a dozen other states, though none became law.
For cancer survivors, this legislative assault is not abstract. Idaho State Representative Brooke Green, a Democrat, is a breast cancer survivor. She was first diagnosed in 2024, a week before her mother was diagnosed with the same disease. She watches colleagues try to restrict the same tools that could save lives. “We are seeing several attempts to address some of the scientific tools that are used to create vaccines, mRNA vaccines and so forth,” Green said. “As a cancer patient, these are life-saving tools that are helping us.” She is thrilled by the new advancements, but she wonders if they will be widely accepted. “There will be some hesitation and some pushback,” she acknowledged. “But look at the flip side: Do you want breast cancer or do you not? Do you want skin cancer? Do you not?” Her question cuts to the heart of the matter. Cancer is not an abstract debate. It is a mother, a dog, a lump found by accident, a phone call that changes everything. For Johnson, the vaccine turned dread into something manageable. She still checks herself, still holds her breath at appointments, still carries a survivor’s wariness. But after five years in remission, she is beginning to believe the future is not just a countdown to recurrence. The technology behind these vaccines is not perfect. Scientists still have years of work ahead before they are widely available, and not all cancers may respond. But the science is moving faster than the trust. The greatest risk is not that the vaccines fail; it is that they succeed and people refuse them out of misplaced fear. That is the lesson of the HPV vaccine, with its millions of missed doses and preventable cancers. The misinformation that surrounded COVID vaccines did not disappear; it is being recycled, repackaged and aimed at the next generation of medicine. If that campaign succeeds, the result could be measured not in clicks or arguments, but in patients who could have been protected and were not. In the end, the story of cancer vaccines is not only about biology. It is about belief. It is about whether a public that has been taught to distrust all vaccines can still see the difference between a lie and a lifesaver. It is about whether people like Chase Johnson, who have already faced the worst, can feel safe enough to hope. Johnson would say yes. Her anxiety has eased. Her life has expanded. Cato may not know what he did, but he found the lump that led to the trial that gave his owner a weapon against the dark. For Johnson, the vaccine was a gift not just of immunity, but of the ordinary, precious ability to think about tomorrow without flinching. That is what the scientists are fighting for. And that is what misinformation threatens to take away.