"The pediatric vaccine is a great victory for modern medicine, but it doesn't cover all strains of disease-causing pneumococcus some of which have recently emerged and are very virulent," said Dr. Pirofski. "This problem, coupled with the fact that herd immunity doesn't protect immunocompromised patients as effectively as people with normal immunity, led us to look for a better vaccine."
The researchers focused on developing a vaccine against serotype 3 a pneumococcal strain that was not included in the pediatric vaccine used for the past decade and that has emerged as a cause of serious pneumonia in adults and children. Serotype 3 can trigger inflammation so overwhelming that it can result in very severe disease or even death.
The goal of this study was to produce a vaccine consisting of a live, attenuated (weakened) version of serotype 3 S. pneumoniae. To create their vaccine, the researchers focused on the serotype 3 gene that codes for pneumolysin, a toxin produced by all pneumococcal strains. The researchers replaced this gene with a synthetic version that they hoped would reduce the amount of toxin produced.
"Our idea was to design a live vaccine that would stimulate the immune system sufficiently to ward off disease but wouldn't lead to the severely damaging inflammatory response that this strain can cause," said lead author J. Robert Coleman, Ph.D., a postdoctoral fellow in microbiology & immunology at Einstein, who helped develop the gene-modification technique, known as synthetic gene customization, while a graduate student at Stony Brook University.
"The novelty of this approach lies in the fact that the gene's expression would be reduced, but not eliminated," Dr. Coleman added. "Previous approaches to genetic regulation of virulence relied
|Contact: Kim Newman|
Albert Einstein College of Medicine