­“Smart” Pneumococcal Vaccine Attacks Only When Needed

A new, experimental, protein-based pneumococcal vaccine allows bacteria to colonize within the body and only attacks when the bacteria begin to pose a threat, according to new research.

Penicillin and other antibiotics are commonly used to treat and prevent illnesses caused by pneumococcus. However, the treatments’ effectiveness has waned over the years, because bacteria have become antibiotic-resistant. The new vaccine, because of its different approach and its capability to counteract over 90 strains of pneumococcus, has the potential to alter vaccine development in the future.
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“Here, we present a ‘smart’ vaccine that leverages our current understanding of disease transition from bacterial carriage to infection with the pneumococcus serving as a model organism,” the researchers said.

The vaccine works by identifying bacteria via proteins attached to their surface, allowing the bacteria to exist until these surface proteins begin to break free of the bacteria, indicating virulent transition. 

Laboratory tests have shown the vaccine to be effective at defending against more than 12 strains of pneumococcus, with computer simulations indicating effectiveness against all strains. The researchers noted that more tests will be needed to confirm the vaccines effectiveness against these remaining strains.

“Aided by a delivery technology capable of multivalent surface display, which can be adapted easily to a changing clinical picture, results include complete protection against the development of pneumonia and sepsis during animal challenge experiments with multiple, highly variable, and clinically relevant pneumococcal isolates,” the researchers conclude.

“The approach thus offers a unique and dynamic treatment option readily adaptable to other commensal pathogens.”

—Amanda Balbi

Reference:

Li Y, Hill A, Beitelshees M, et al. Directed vaccination against pneumococcal disease [published online June 6, 2016]. Proc Natl Acad Sci U S A. doi:10.1073/pnas.1603007113.