NATIONAL HARBOR, MD -- Studies indicate that pneumococcal vaccines reduce pneumonia cases by 20 to 35 percent, according to Mark Alderson, the Director of the Pneumococcal Vaccine Project at PATH, at the World Vaccine Congress 2011. Even though all three approved pneumococcal vaccines are conjugates--Prevnar, Synflorix and Prevnar-13--he sees promise for cheaper, more effective vaccines created from proteins instead of polysaccharides. And Alderson says protein vaccines have "the potential for breadth of coverage against all serotypes [of pneumococcal disease.]"
Unlike conjugate vaccines, which combat a small percentage of the 90-plus pneumococcal serotypes and usually focus on those more prevalent in North America, protein vaccines could utilize a handful of protein carriers instead of hundreds of assays to cover a wider number of pneumococcal strains, including those that are common in developing countries. Alderson specifically highlighted the potential for pneumolysoids, which are toxins, as a protein carrier. "It's an interesting protein because it has some interesting biological properties," Alderson said. "It is also involved in complement activation and has been described as having adjuvant properties."
While creating thermostable vaccines is important, it's not PATH's main priority. "The real short-term push is to get lower-cost vaccines out as quick as we can," Alderson said. "The challenge is when you [bring in the technology] and not doing it too late."