San Francisco (AFP) – Facebook and Twitter took aim at US President Donald Trump and his campaign Wednesday over a video post in which he contended that children are “almost immune” to the coronavirus, a claim they said amounted to “misinformation.”In an extraordinary move, Facebook removed the clip from the president’s account — the first time it has taken down one of his posts for violating its content rules.The video — an excerpt from a Fox News interview — “includes false claims that a group of people is immune from COVID-19 which is a violation of our policies around harmful COVID misi…