Massachusetts health authorities took the unprecedented step yesterday of deputizing dentists, paramedics, and pharmacists to help administer vaccines against both the seasonal flu and the novel swine strain expected to make a return visit in the fall.

“There’s a workforce issue, but there’s also a significant communication and education issue so that the public can clearly understand there’s a difference between the seasonal flu vaccine and then dose one and dose two of your H1N1 vaccine,’’ said Jim Blumenstock, an executive at the Association of State and Territorial Health Officials.

Hoping to bolster the army of health professionals capable of vaccinating patients, the state Public Health Council -an appointed body of doctors, consumer advocates, and policy specialists - voted unanimously yesterday to enlist medical workers not normally involved in flu immunization campaigns. That could add up to 21,000 volunteer dentists, pharmacists, and paramedics.