Have you ever had food poisoning? Actually, a better way to ask it is: have you ever been POISONED BY FOOD?! If you have been afflicted with a case of foodborne illness, you probably know all too well that the body's reaction is typically to try to get the source of the poison out! And you know what that means …
The Centers for Disease Control and Prevention (CDC) estimates that one in six Americans (50 million) experiences foodborne illness each year, and violent vomiting is often the result. Ugh. Most cases involve disease-causing microbes that are either bacteria or viruses (often called pathogens) that get into the food that people eat. (By the way, drinks can cause "food" poisoning, too!)
The CDC offers good recommendations for preventing pathogens from getting into food, including washing your hands when preparing food and before eating! However, you can't always count on others to take all of the right precautions. Here's where research on the ISS comes in. Scientists are working on paths to prevent pathogens from making us sick — paths in the form of vaccines.
Vaccines are medicines that people can take so they don't get certain diseases. They can also make the effects of diseases much less severe. During the last century, vaccines wiped out diseases like:
- RUBELLA that had previously caused birth defects and deaths in tens of thousands of children;
- POLIO that had previously paralyzed hundreds of thousands (mostly children);
- SMALL POX that had previously killed millions.
Many consider vaccines the most successful medical advancement in this history of public health! This century, we are sure to develop more vaccines with the help of the microgravity of the ISS.
So … how do vaccines work? Vaccines trick the body — okay they TEACH the body. There are certain diseases like chicken pox that if you get them once, you won't get them again. That's because the body's immune system figures out how to fight them if they ever come back. Vaccines take that idea and introduce the body to certain diseases by using elements of a disease-causing pathogen (or cells that closely resemble a pathogen). Vaccines give the body just enough "taste" of a disease (pun intended) that a person doesn't get sick but that person's immune system can still learn how to fight it off in the future.
So in addition to understanding the human immune system, developing a vaccine requires an understanding of a pathogen's cell structure, growth rates, and its defenses to help it survive. That requires research on a pathogen's genetic makeup. Here's where the ISS is helping scientists (gene genies) develop a taste for new vaccines. (Yes, pun intended again.) Research in the space environment has demonstrated that scientists can bring about key changes in the cells of pathogens — changes that they have not been able to observe on Earth.
Thanks to microgravity and to a better understanding of pathogens' genes, scientists have been more effective in altering the growth rates of the cells of pathogens. Once we eat contaminated food, the microbes (bacteria or viruses) of many foodborne illnesses multiply rapidly in our bodies, so being able to slow down the rate they multiply is really important. Scientists have also been able to alter cells in pathogens so they're not as "virulent," which means that the pathogens aren't as powerful in making us sick.
Salmonella is one pathogen that scientists have learned a lot about in microgravity. It is one of the more common forms of food poisoning in the U.S. Worldwide, Salmonella diarrhea is the third leading cause of infant mortality. (So the consequences of foodborne illness can be worse than violent vomiting.) You might also have heard about recalls of food due to fears of Salmonella infection. You might not be bummed out when they recall spinach, but peanut butter is probably a different matter!
Food recalls can be slow because they can't happen until there are diagnosed cases. So a vaccine for Salmonella would make a dramatic impact on global health. The vaccine is undergoing tests with people getting the vaccine to see how well it works and to try to determine if there are any negative side effects. So it looks incredibly promising for a Salmonella vaccine. Plus, scientists on the ISS believe that they're moving closer and closer to unlocking the keys to developing vaccines and treatments for other pathogens. They are like gene genies, after all!
