Now, we'll move on to describe vaccines and development against
a highly complex pathogen, Staphylococcus aureus.
This pathogen causes disease by expressing a number of virulence factors.
S.aureus causes a wide spectrum of diseases ranging from
relatively mild skin infections to life-threatening wound and bloodstream infections.
It is a leading cause of morbidity and mortality
in both healthcare-associated and community settings.
In surgical patients, S.aureus infections
are associated with high morbidity and mortality,
prolongation of hospital stays and an increase in healthcare costs.
We also noted increases in antibiotic resistance,
most notably, methicillin resistance.
There is an alarming increase in community-acquired infections as
well in many settings, including pediatric populations.
I also listed on the slide,
populations that are at high risk of S.aureus infection.
Now, Staphylococcus aureus is a challenging vaccine target.
It's a highly successful commensal organism,
and about 30 percent of humans are colonized with Staph aureus.
Staph aureus exhibits a diverse array of
virulence factors that facilitate colonization and evasion of host immune responses,
such as toxins and adhesion factors;
it is a master in scavenging nutrients from the host,
it exhibits capsular polysaccharides to evade phagocytosis,
and it also has a number of virulence factors that
interfere with appropriate immune host-mediated immune response.
Staph aureus shows extensive strain diversity.
Most humans actually fail to generate
functional antibodies against S. aureus following natural exposure,
be it by colonization or infection.
The importance of this,
I will describe it a little bit later on.