Sens. Amy Klobuchar (D-MN) and Tina Smith (D-MN) have written to GlaxoSmithKline (GSK) CEO Emma Walmsley to urge the drugmaker to do more to increase inventory levels of GSK's recombinant zoster vaccine (Shingrix) in the wake of a shortage. The senators said GSK may have failed to create "contingency plans" to ensure sufficient supply for the launch of its new shingles vaccine. Klobuchar and Smith also expressed concern that patients may not be able to complete their recommended schedule of two doses in 6 months. After GSK received approval for the vaccine last fall, CDC's vaccine advisers recommended the new vaccine over Merck's older shingles vaccine, zoster vaccine live (Zostavax). GSK says it has a "fair and equitable" process to ship the vaccine, which includes order limits, and is delaying "broad consumer education activities" such as television ads until it can restore supplies.