GENEVA, Oct 21 (Reuters) - A World Health Organization (WHO) advisory group is studying decisions in Sweden and Denmark to halt vaccinating young people with the Moderna (MRNA.O) COVID-19 vaccine after "very rare" myocarditis in some and a statement was expected soon, WHO"s assistant director-general Mariangela Simao said on Thursday. Work on a review of Sputnik V vaccine made by Russia"s Gamaleya Institute for possible WHO emergency use listing has restarted, after being on hold due to a "legal procedure", she told a news briefing. Further inspections were planned in the next few weeks and additional clinical data was expected.