For years, scientists have attempted to discover what destroys pneumococcal bacteria after a person has been vaccinated. In a recent study, vaccinologists in the U.S., China, and Switzerland, found the answer.
The international team found evidence that pneumococcal bacteria are destroyed in the liver after vaccination.
An additional and unexpected result found that a pair of cells prevented disease prior to its onset. The team then followed through by thoroughly investigating the two pneumococcal vaccines and their role in destroying streptococcus pneumoniae. The two most prominent pneumococcal vaccines are PPV23 and PCV13.
The latter is a conjugate vaccine. Number 13 indicates that the vaccine protects against 13 streptococcus strains. There are two subunits in conjugate vaccines. One is the weak antigen and the second is the strong antigen known as the carrier unit.
It had previously been determined that PCV13 is more effective than PPV23 due to PCV13 creating more lgG antibodies, the most common type of antibody found in blood circulation. Juanjuan Wang, M.D., the lead author of the study noted that vaccines have proven to be the ultimate protection against pneumococcal infections.
The study was published in the journal Science Translational Medicine and reported recently in MedicalXpress. Vaccines targeting bacteria kill disease and save lives. Immunizations that repel bacterial infections fight diphtheria, pertussis and tetanus, together with the pneumococcal vaccines.
The second vaccine being analyzed, PPV23, is a polysaccharide vaccine known as pneumococcal polysaccharide vaccine that protects 23 strains. This vaccine was designed to expose the immune system to sugars that create a pathway on the surface of almost two dozen streptococcus pneumoniae strains.
When comparing both vaccines, the PCV13 formulation was associated greater efficacy with hepatic endothelial cells capturing circulating pathogens. Further, PCV13 fostered more IgG antibodies and engaged Kupffer cells and the liver’s epithelial cells.
Kupffer cells destroy invasive microorganisms. They are white blood cells found in the liver and adhere to the blood vessels’ endothelial cells. Endothelial cells (epithelial cells) line the walls of blood vessels.
The researchers confirmed that endothelial cells and Kupffer cells captured streptococcus pneumoniae through a “zipper type” mechanism prior to destroying them.
Dr. Wang concluded that technical modifications, the team’s findings may be used to evaluate similar vaccine candidates.
