According to an FDA drug shortages report, the US shortage of sumatriptan nasal spray due to a shortage of active ingredient that was first reported in November 2015 should be completely resolved by February 2017.
At this time, both GlaxoSmithKline and Sandoz are reported to have 5 mg/spray versions of the nasal spray available, and GSK has the 20 mg product available as well. Sandoz reports that it has limited availability of the 20 mg product and expects full availability by February 2017.
View the FDA drug shortage report.