True breakthroughs in science are few and far between. What does it take to break new ground in science? Scientists on one path suddenly discover reason to detour onto another, one they never intended to travel — a road that may lead nowhere. Some are the consequence of a happy accident paired with curiosity.

It is not uncommon for scientists to have a specific goal in mind when they work on important breakthroughs. Sometimes early in one’s career, one gets an idea that can’t leave their head. They tell themselves it’s ridiculous, but can it actually be done? Respected peers frequently remind them of all the reasons their proposal can fail and how this could have a negative impact on both their personal and professional reputations. Although the message is grim, the concept will not perish. It’s a gamble, therefore they’re looking for financial backers and colleagues who are ready to take the chance with them. In some cases, it can lead to key discoveries like penicillin and mRNA vaccines.

In 1928, Dr. Alexander Fleming was growing bacteria in a laboratory dish at St. Mary’s Hospital in London. Fleming did not have a scientific goal in mind. Just doing what he had to do as a microbiologist.

In the meantime, another type of microbe had arrived in the air, landed on the laboratory dish, and began to develop and spread there, as if it were a fungus. Fleming discovered that the fungus was destroying the bacteria as it was growing. He came to the conclusion that it was creating a chemical that would destroy the bacteria. He termed the chemical the fungus was producing “penicillin” because its scientific name was Penicillium rubens.

Few people were interested in Fleming’s discovery when he wrote a paper about it. Ten years after the discovery of penicillin, another group of scientists attempted to produce big amounts of the antibiotic to test if it could treat bacterial illnesses and save lives. We’ve all seen how that turned out, after all.

It wasn’t that Fleming had a great thought and yelled “Eureka!” that led to Fleming’s scientific success. As it turned out, it happened because he spotted something and stated, “That’s odd,” and then tried to figure out what the problem was.

Like the Pfizer/BioNTech and Moderna vaccines for COVID-19, the narrative of mRNA vaccines is fundamentally different from that of penicillin. There have been a few scientists over 30 years who feel that mRNA vaccines could have enormous advantages over regular vaccines if only a few difficulties could be addressed. A significant number of these scientists gave up when they ran into these roadblocks, but a select few continued and were rewarded with success.

It was in the early 1990s when Dr. Katalin Karikó joined the University of Pennsylvania’s faculty with the goal of developing an anti-viral mRNA vaccine. She applied for grants to help fund her research but was continually turned down: the reviewers said that financing her research would be a waste of money because it was so unlikely that she or anyone else could overcome the difficulties. If she took a pay decrease and a demotion, her university would continue to fund her work. Both were accepted by her, and she pursued her goal with tenacity.

As a researcher, she was particularly interested in the immune system’s strong reaction to mRNA from viruses. Karikó and colleague Drew Weissman worked tirelessly for ten years to discover how to create a modest alteration in mRNA that prevented this dramatic immune response — an important step toward the creation of all mRNA vaccines. In the absence of this, there would be no mRNA COVID vaccines on the market today.

After meeting and falling in love with each other, two of the scientists behind the Pfizer/BioNTech COVID vaccine—Uur ahin and zlem Turci—fell in love with the concept of generating an mRNA vaccine. The Wall Street Journal reports that the couple were married in 2002, took a lunch break, and then returned to their lab to continue an experiment, one of many over the course of 30 years. Their ultimate goal was realized in 2020 when their mRNA vaccination for COVID-19 confirmed safe and efficacious after a series of successful experiments.

As with Fleming, Karikó, Weissman, ahin, and Turci, scientists who make life-saving discoveries often face disinterest or repeated skepticism and derision. Despite the odds, these scientists were able to realize the visions they had for their work in the first place. In addition to fame and fortune, they have gained the knowledge that millions of people around the world have avoided illness and death as a result of their work.

Of course, pursuing an implausible goal isn’t always a success for scientists. In the end, even though their ideas were great, nature didn’t operate the way they planned. A merciless gang of facts kills their lovely theory in the end.

If only they had done the experiment a little differently, if only they had persevered a little longer, or if only they had not run out of financial support, some scientific dreamers may have realized their goals sooner rather than later. As a result, until other scientists rediscovered their work years later, neither they nor the rest of us benefited from what might have been.

Only when society is ready to invest in dreamers and recognizes that not all investments will lead to great breakthroughs can scientific breakthroughs be achieved. A considerably bigger return on investment is generated by efforts that lead to breakthroughs, as well as the prevention of misery and death and the transformation of the world.