Still one of the best visual representations of herd immunity I've come across #vaccineswork #publichealth #healthpic.twitter.com/GHL4tgcPHk
11:16 PM - 13 Apr 2016
0 replies
4 retweets
4 likes
Loading seems to be taking a while.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.