Space-Based Vaccine May Go to Human Trials

by Clara Moskowitz, Staff Writer

Date: 23 September 2009 Time: 09:06 AM ET

Discovery STS-119 mission specialist John Phillips with a Salmonella vaccine experiment
CREDIT: NASA

A vaccine created from research in space may soon be put to the test in human trials for the first time.

The Astrogenetix company, based in Austin, Texas, has begun applying for approval to begin testing their space-designed salmonella vaccine on humans. Salmonella are disease-causing bacteria responsible for about 40,000 infections in the United States each year, according to the Centers for Disease Control and Prevention. Eating contaminated food is one primary means of infection.

"If all the stars are aligned, we could potentially be in human trials sometime next year," said Astrogenetix CEO John Porter. "That's a real milestone."

The company created its vaccine candidate based on research conducted on NASA's space shuttle flights. Astrogenetix has sent up experiments on 23 shuttle missions so far - most recently on Discovery's flight earlier this month. The company plans to continue with the six remaining missions on NASA?s current schedule.

If their vaccine gets approval to go forward with human trials, it will be the first time a medicine created from space-based research has gone that far.

Stronger bugs in space

The key to new vaccines lies in an important difference in the way things grow in space. Many bacteria and viruses have been shown to grow more quickly in the microgravity of space, as well as become more virulent or more infectious.

"We don't fully understand why these bugs show increased virulence," Porter told SPACE.com. "But when you see increased virulence it helps you to target potential therapeutic candidates at a particular disease."

The changes that occur in weightlessness help speed up experiments, and help point researchers toward the causes of virulence, not just in space but on Earth as well.

Astrogenetix scientists have used their experiments to try to hunt down the genes responsible for virulence in various diseases. Once they have identified potential genes responsible, they can try to remove those genes to create a vaccine.

"A vaccine is the bacteria itself, but changed in some way so that it doesn?t have the same infectious characteristics, so you can expose the body to it but not make a person sick," Porter said. "Once we can determine the genes that are the root cause of virulence, we can delete the gene to delete the virulence."

That's just what Astrogenetix did for salmonella. Over the course of many experiments, researchers homed in on a pattern of genes that seemed to be responsible for virulence in the bacteria, and then removed them to create a test vaccine.

Astronauts aboard space shuttle flights helped carry out the research. Once in space, an astronaut would activate the experiment, beginning the growth cycle of the bacteria. Simultaneously, a control experiment would run on the ground. Once the shuttle flights landed, Astrogenetix would collect the canisters carrying the experiments, and analyze the data.

Other illness in the crosshairs

Astrogenetix doesn't intend to stop at salmonella. Its scientists are also hard at work on a vaccine to prevent infection from Methicillin-resistant Staphylococcus aureus (MRSA) - a bacterium that causes a certain type of staph infection. This strain is common in hospitals, and is especially hard to treat because the bacteria are resistant to a large number of antibiotics.

"It?s a really bad disease," Porter said. "Our research shows that 19,000 people in the U.S. alone die from this a year."

The researchers are still in the information-gathering phase, trying to close in on the genes responsible for its infectious nature. Astrogenetix's last MSRA experiment flew on the STS-128 mission of the shuttle Discovery, which landed Sept. 11.

The company hopes to continue this work both on future shuttle missions, and on long-duration experiments on the International Space Station.

"We're designing medicines using the microgravity environment of space, but these medicines are for use on Earth," Porter said. "These are true medicines that can be pushed out in the world."