Using only three linked sugar molecules, German researchers have created a potential vaccine against an aggressive and antibiotic-resistant strain of Streptococcus pneumoniae — a discovery that eventually strengthen current pneumonia vaccines.
Unlike traditional vaccines made from parts of microbes, the new potential vaccine is entirely lab-made, reducing the amount of work and associated production costs. Researchers who created the vaccine at Potsdam’s Max Planck Institute for Colloids and Interfaces are now partnering with Vaxxilon, a Max Planck spinoff, to develop the vaccine for human use.
“The production of conventional vaccines against ST8 is difficult,” institute director Peter Seeberger said in a press release, referring to Streptococcus pneumoniae serotype 8. “Therefore, the development of a synthetic vaccine would be an enormous medical advance.”
Seeberger, who has a long track record of synthetic vaccine development research, led the current study.
The research team used its knowledge of what the bacteria’s surface looks like to compose the vaccine. Sugars on bacterial surfaces have long been used to produce vaccines, but isolating only the sugars that trigger an immune response is a labor-intensive and expensive task.
To learn which sugars of ST8 are relevant for an immune response, the research team first used an automated synthesis method to produce different sugar molecules found on the surface of the ST8 bacterium. Next, they explored which of these sugars are recognized by the antibodies that normally target the bacterium.
They also had to make sure that the sugars recognized by antibodies triggered an immune response, since some sugars boost the production of antibodies that do not protect against disease.
They found that a combination of three sugars — two glucose and one galactose molecules — triggered an effective immune response against ST8 in mice. Also, when adding the sugar molecules to Prevnar 13, a vaccine that protects against 13 other types of Streptococcus pneumoniae bacteria, mice also got protection against ST8.
“Synthetic carbohydrate vaccines represent a paradigm shift within vaccine research,” Seeberger concluded. “They are more precise, effective and easier to manufacture than conventional vaccines.”