A new vaccination with recombinant M. tuberculosis PknD subunit offers a novel strategy to protect against TB meningitis, according to a team of researchers at Johns Hopkins University School of Medicine.

The experimental vaccine works against certain lethal strains of TB that are marked by the presence of a protein known as PknD, which helps the TB bacterium sneak past the blood-brain barrier, according to researchers.

Specifically, PknD makes TB virulent by allowing it to attach to, damage, and penetrate the protective cells that line the small blood vessels of the brain and prevent toxins and bugs traversing the blood from invading the organ.

If proven effective in people, the vaccine also could be used to boost the brain-protective effects of the traditional BCG vaccine, the only currently available anti-TB vaccine, the efficacy of which varies greatly, according to researchers. Because it is made with PknD protein chunks, this vaccine could be given to people with weakened immune systems; this is not possible with the BCG vaccine, because it contains live bacteria.