You don't want to use your 7 month old to find out! Tetanus is caused
by a toxin produced by the growing C tetani bacteria. If there is
enough toxin in the infant's bloodstream to induce immunity, it is a
sure bet that there will be a sufficient amount to produce disease.
It takes several days to weeks to mount a protective immune response
to a first exposure to toxin. By this time the bacteria will have
produced sufficient toxin to produce clinical disease in this infant.
Jay Mone'
