15 April 2009
Vaccine developed for E. coli diarrheal diseases
by Kate Melville
A researcher from Michigan State University (MSU) has developed a working vaccine for enterotoxigenic E. Coli, which is responsible for the deaths of 2 to 3 million children each year in the developing world. It also causes health problems for U.S. troops serving overseas and is responsible for what is commonly called traveler's diarrhea.
"This strain of E. coli is an international health challenge that has a huge impact on humanity," said vaccine creator A. Mahdi Saeed, a professor of epidemiology and infectious disease at MSU who spent four years developing the vaccine. "By creating a vaccine, we can save untold lives. The implications are massive."
Saeed's breakthrough was discovering a way to overcome the miniscule molecular size of one of the illness-inducing toxins produced by the E. coli bug. Since the toxin was so small, it did not prompt the body's defense system to develop immunity, allowing the same individual to repeatedly get sick, often with more severe health implications.
In developing the vaccine, Saeed created a biological carrier to attach to the toxin that once introduced into the body induces a strong immune response. This was done by mapping the toxin's biology and structure during the design of the vaccine. After creating the carrier, Saeed tested it on mice and found the biological activity of the toxin was enhanced by more than 40 percent, leading to its recognition by the body's immune system. After immunizing a group of 10 rabbits, the vaccine led to the production of the highest neutralizing antibody ever reported for this type of the toxin.
Saeed hopes that human clinical trials can begin later in the year. He also said that the vaccine will be of benefit to farmers, as the E. coli bug is a major cause of sickness and death for newborn animals such as calves and piglets.
Source: Michigan State University