Kelley:

Perchance my "poor grammar" prevented you from reading my entire comment. Let me re-post the most pertinent part as it relates to your "baby bottle" analogy:

"... a single exposure to a small volume containing parts-per-billion levels of mercury..."

Operative terms: "single exposure" and "small volume". Unlike feeding from baby bottles (how many times a day for how many months?) a vaccination is a one-time event. Also, unlike feeding from baby bottles (~200-300 milliliters per bottle?), a typical vaccination volume is 1 milliliter or less.

I dare say the two are not equivalent, but that's a nice reference for that argument.