Hope for millions

A new generation of salmonella-based, single dose vaccine candidates to fight infant pneumonia

Infectious disease causes 35 percent of deaths worldwide, and is the world’s biggest killer of children and young adults. Among them is bacterial pneumonia, a prodigious killer causing more than 2 million annual fatalities worldwide.

Now, an international team led by ASU Professor Roy Curtiss hopes to turn a foe into a friend by enlisting Salmonella, the leading cause of food poisoning, in the fight against bacterial pneumonia. In June 2005, Dr. Curtiss received a $15 million dollar award (Grand Challenges in Global Health Initiative) to develop an anti-pneumonia vaccine for newborns.

The project team has curbed Salmonella’s appetite for infection and used it as a delivery vehicle that hosts a suite of key antigens—surface proteins of Streptococcus pneumoniae, the causative agent of bacterial pneumonia. In the body, these antigens stimulate an immune response, but the additional pathogenic ingredients necessary to cause the disease are absent. Such next-generation vaccine candidates offer new promise in the battle against S. pneumoniae.

In addition to triggering a powerful, protective immune response, Salmonella-based vaccines offer an inexpensive alternative that may be administered orally in a single dose and require no needles or refrigeration—a significant advantage in the developing world.

The first generation of this vaccine is currently undergoing a phase one clinical trial in St. Louis entitled Recombinant Attenuated Salmonella Typhi Vaccine Vectors Producing Streptococcus Pneumoniae PspA.