If you have seen "It's started" somewhere, you need to know that it's a contraction of "It has started", not "It is started".
"The business is started by him"
"He started his own business"
This is transitive of 'start', isn't it?
I think it is correct to say 'the campaign has started', where someone started the campaign.I would say intransitive "to start" for something natural and no one does it
Have you ever heard of 'artificial rain'?(It's impossible for someone else to start a rain)
I think it is correct to say 'the campaign has started', where someone started the campaign.
Not a teacher.
A campaign is a series of activities, so I would simply say 'the campaign has begun'.the campaign has begun its activity