Lost of charm here, Sam :) Finesse required in terms of the actual design/placement etc of the various speed bubbles, as at times, compositionally, this element did seem a little random and ad-hoc, whereas comic book panels ensure the speech stuff is adding to the dynamism of the scene. It does seem a pity too that the transformation at the end isn't shown, as characters transforming into more powerful iterations of themselves is a trope of comic book heroes too and would, in fact, be a 'bigger' moment in the comic. I'll send your url to Dr Klappa re. the accuracy of what you've depicted.
I love your animation Sam!!!! Well done!!! The only (very minor) comments I would make is that the macrophages usually eat some of the invaders and then present parts of the killed invaders to the B- and T-cells. B-cells become activated and turn into plasma cells, which then secret loads of antibodies. These antibodies stick to the invaders and T-killer cells and more macrophages will finish the tagged invaders. T-helper cells often assist the B-cells to recognize the presented parts on the macrophages. Once the job is done, the plasma cell will turn into a memory B-cell, which does not longer produce antibodies, but instead hangs around in case it is needed again. Here is more or less the long version https://en.wikipedia.org/wiki/B_cell Does this make sense?