Anti-vaccine activist Robert F Kennedy Jr launches presidential campaign

Robert F Kennedy Jr (Hans Pennink/AP)

Anti-vaccine activist Robert F Kennedy Jr has launched his longshot bid to challenge US President Joe Biden for the Democratic nomination next year.

Mr Kennedy, a member of one of the country’s most famous political families who has in recent years been linked to some far-right figures, kicked off his campaign in Boston on Wednesday and likened his campaign to the American revolution.