OTTAWA (CBC) - Three more people with H1N1 swine flu have died in B.C., and the number of serious cases nearly doubled over the past week, officials with the B.C. Centre for Disease Control report in the weekly swine flu update.

The three deaths bring the total number of deaths linked to the disease in the province to 15, but in all but one of those cases, the patients had underlying medical conditions, health officials confirmed on Tuesday

Officials also released new totals for the number of severe cases H1N1 identified in B.C, showing the number of serious infections has spiked dramatically since Oct. 27.

The figures showed:

Health officials began vaccinating high-risk groups across B.C. last week, but say a shortage in the supply of the vaccine may last into December.