Learn a little about meningitis. Start with the link below and scroll through the pages listed on the right of the
page to begin to understand meningitis and meningitis vaccine options.
http://www.meningvax.org/about-meningitis.php
On the following page, more information is given about the MenAfriVac vaccine.
http://www.meningvax.org/developing-conjugate-vaccine.php
What are the two components of the MenAfriVac vaccine? Why are both included in the vaccine?
For group A Neisseria meningitidis, the major virulence factor is a polysaccharaide that is comprised of a
repeating unit of partly O-acetylated-1,6-linked N-acetylmannosamine phosphate. It is a mannose in its
pyranose form with a phosphate at the 6 position, an N-acetyl group at the 2 position, and either an H or acetyl
groups at the 3 and 4 position (this is the "partly O-acetylated " part). A Fischer projection of mannose is shown
below. Draw the partly O-acetylated-1,6-linked N-acetylmannosamine phosphate.
Now check your work against Figure 2 in "Epidemic meningitis due to Group A Neisseria meningitidis in the
African meningitis belt: A persistent problem with an imminent solution". Here is the link to that article:
http://www.sciencedirect.com/science/article/pii/S0264410X09006161
To make a conjugate vaccine, this sugar must be attached to a protein. One method for doing this is to react the
reducing end of the sugar with the free amino group of a lysine.
Redraw your sugar in the reactive, open chain aldehyde form, of its reducing end. Draw a lysine next to it.
Reacting a primary amine of a protein with a reducing sugar produces an imine, which is a functional group that
contains a carbon-nitrogen double bond. For vaccine production, this bond would be reduced to a single bond.
Draw the final product of the reaction of the two molecules you drew above.