Pneumococcus vaccine
The vaccine candidate is a protein-based vaccine derived from our proprietary Antigen Identification Program® (AIP®) and is based on selected antigens which are highly conserved among different clinical isolates of the bacterium.
A Phase I clinical trial was initiated in 2009. In the first-in-man trial with a focus to obtain safety and immunogenicity data, 32 healthy adults were vaccinated with Intercell's investigational vaccine. The initial analysis of the data has indicated a good safety and tolerability of the vaccine candidate, which was confirmed by a Data Safety Monitoring Board. The vaccine was immunogenic, and antigen dose-dependent induction of antibodies was confirmed for all three proteins of the vaccine.
The selection process of antigens was described and published in the Journal of Experimental Medicine in January 2008. The two lead candidates were found to be exceptionally conserved among clinical isolates (>99.5 percent identity), cross-protective against different serotypes in lethal sepsis and pneumonia models, immunogenic in both elderly and young children and play important, non-redundant roles in bacterial multiplication. In addition, the authors report for the first time opsonophagocytic killing activity for antibodies induced by proteinaceous pneumococcal antigens that is a promising in-vitro assay for potential surrogate markers.
Primarily target groups for the novel vaccine are children in the developing world, where development is being funded by the U.S.-based non-profit organization PATH, and elderly people in the developed world.
About Streptococcus pneumoniae
Streptococcus pneumoniae, or pneumococcus, is a gram-positive, encapsulated bacterium and the most common bacterial infection in both industrialized and developing countries. It is the most frequent cause of pneumonia worldwide. It accounts for most cases of bacterial meningitis in adults and it is the most common cause of bacteraemia, pneumonia, meningitis and otitis media in young children. In addition, it causes illness and death among the elderly and immunosuppressed individuals. For children younger than 5 years, it is the most common vaccine-preventable cause of death.
The bacterium is surrounded by a polysaccharide capsule and based on the differences in the composition of the capsular polysaccharides, more than 90 different serotypes have been described. Current data on pneumococcal disease in infants suggest that the 11 most common serotypes are responsible for at least 75 percent of invasive diseases. However, serotype distribution varies with age, disease and geographical region, which complicates the vaccine development.
Current treatment and prevention
Invasive pneumococcal disease is traditionally treated with antibiotics. Consequently, the emergence of multi-resistant pneumococcal strains in recent years has complicated disease management. Also, even with the use of effective antibiotic therapies, mortality rates are as high as 80 percent for patients in high risk groups.
There are two vaccines on the market recommended for different ages. A heptavalent conjugate vaccine (Prevnar / Wyeth) for children younger than 2 years targets seven serotypes of pneumococcus which account for 80 percent of all pneumococcal invasive disease in this patient group in the United States. There is also a 23-valent polysaccharide vaccine (Pneumovax / Merck) approved for use in adults (recommended age 65 years and older) which contains capsular antigens from 23 of the most common strains. Still, the vaccines are expensive and target only a limited number of the more than 90 different serotypes of the bacterium.
Latest News
Partners
- In-house