Most vaccines are one-size-fits-all — you get the same flu shot, no matter who you are. But in the future, what if you could order a cancer vaccine specifically created for your genetic code?

In a study published today in the journal Nature, German researchers are describing a technology, known as an RNA vaccine, that could help make that possible. They've also developed an algorithm that helps them quickly figure out how to engineer a vaccine for any type of cancer.

"We were interested in not only providing a solution for a few patients, but to develop an approach that is applicable and scalable for many, many patients," said Ugur Sahin, the managing director for translational oncology at the University Medical Center of Johannes Gutenberg University and the lead author of the study. "We have a blueprint for a universal approach."

For now, their technology has only been shown to work in mice for a few cancer types, but it could theoretically also work in humans down the line.

Before we delve into how the treatment would work, here are some basics: One way to think about cancer is as an internal, never-ending genetic infection — a cell's DNA mutates in a way that makes the cell multiply incessantly, eventually creating so many cells that a tumor forms. When the immune system detects a foreign substance, like a virus or bacterium, it sends various types of defense cells to kill it off. And over time, your immune system learns to recognize repeat intruders, and develops defenses for each specific one. That's what keeps you from getting the same cold every year.


In theory, the immune system could also learn to recognize cancer. But often, the cancer grows too quickly for it to respond in time. So, for years, scientists have been trying to develop ways to help jumpstart an immune response to fight tumors.

That's where RNA comes in. RNA is really easy to synthesize in the lab quickly, says Sahin. Recent advances in RNA-making technology have also made synthetic RNA more stable, and thus a better fit for vaccine development, than ever before. (DARPA, the Defense Department's research arm, is developing RNA vaccines to fight ebola and other diseases, for example.)

RNA is the molecule responsible for translating your genetic code into the proteins that make up your cells. And it's essentially a single-stranded copy of DNA, so it contains all of DNA's genetic imperfections, including the cancer-causing ones. The reason RNA vaccines are so promising is because, unlike protein-based vaccines (which involve scientists manufacturing antigens in a lab and injecting them into patients' bodies), they actually exploit cells' protein-creation process, and turn the body itself into an antigen factory. If you can get RNA that churns out disease-fighting proteins instead of normal ones, you can jump-start an immune response.


That's essentially what these researchers did. For this study, the researchers injected one set of cancerous mice with mutation-containing RNA, and another set of cancerous mice with normal RNA as a control group. Then they waited for the mice's own protein factories to start churning out mutated proteins.

The results were good. About two-thirds of the cancerous mice treated with the RNA vaccine were still alive at day 100, while all the ones injected with control RNA died within 65 days, according to the study. What's more, the researchers engineered a combination RNA vaccine that encompassed five of the mutations their algorithm predicted would best induce an immune response. Thirty days after they injected that vaccine into sick mice, 80 percent of them were still alive. All of the control mice had died.

For the last year, the researchers have been testing out their technology on human melanoma patients. The idea is to sequence their individual tumors and create personalized vaccines for them on-demand. Sahin wouldn't say how the trial was going, but he hinted things looked promising. All he would say is, "I think we are pretty close to a nearly perfect vaccine approach."


There has been hype about RNA vaccines in the past with little pay-off. There's no guarantee that this latest method will work at scale, either. But if these personalized cancer vaccines do prove to be effective and safe in patients, it could be the first step in saving millions of lives.

Daniela Hernandez is a senior writer at Fusion. She likes science, robots, pugs, and coffee.