Some of the alternative terms suggested by Twitter wits include "plague enthusiast," "child cemetery advocates" and "infant infectors."
The longtime HBO host promoted the views of a well-known vaccination skeptic on his Friday night show.
The actress lobbied in California with Robert F. Kennedy Jr. against a bill that would curb fraudulent exemptions for anti-vax parents.
A spokeswoman told HuffPost the company is cracking down on hashtags attached to posts containing factually incorrect content.
Health officials in Orange County, California, are warning moviegoers who saw a midnight screening of “Avengers: Endgame” that they may have contracted measles from an infected audience member.
“I just don’t understand the mindset of people who want to spread fear," Joshua Nerius said of anti-vaxxers, "who are willfully deciding to ignore the facts."
Ethan Lindenberger spoke to a Senate committee about vaccine misinformation after measles outbreaks in the U.S. and abroad.
Hundreds of anti-vaxxers descended on Washington's capital amid the state's worst measles outbreak in decades.
The state has seen a huge rise in non-medical vaccine exemptions since 2003.
"I’m pretty sure that in the world’s most vulnerable places, these moms wouldn’t even think twice.”