Long lines at Southern Nevada Health clinics have prompted an increase in H1N1 vaccines. Doctors are expected to recieve more doses of the vaccine in the next few weeks. The Health District is holding two immunization clinics Saturday for those in priority groups, from 9 a.m. to 6 p.m. at Foothills and Centennial High Schools. The district has also now added adults with pre-existing medical conditions to the list of priority groups. Those groups already include pregnant women, emergency and healthcare workers, and young people between six months and 24-years-old.