I don't particularly like or hate this post, but if you are not allowed to downvote a post you don't like - just because it's about vaccines - then you have created a sort of taboo.
For instance, I literally don't get this post so don't find it humorous, so I could downvote and that would have nothing to do with my opinion on vaccinations.

I always identify jokes by the presence of comedic value

Ah now I see the funny, it's the 3 layers deep irony with his usernname :)

I hope some day people will discover the white text with black border. The one everyone uses except for this meme for some reason.

Then it must be my face that's depressed, depressed from looking at your smug happy face

Doesn't this make him correct for once

And then the whole school clapped

Oh your XDDDD was ironic.