Shingrix, the preferred shingles vaccine, is in short supply in the U.S., Web MD reports.
Supplies of Shingrix have not kept pace with demand, and the vaccine's maker, GlaxoSmithKline, expects shipping delays and order limits to continue through 2018.
While the older shingles vaccine, Zotavax, is not in short supply, Shingrix provides up to 90 percent greater protection and last longer, so providers prefer it for their patients.
The new vaccine was approved last fall by the FDA and is recommended by the CDC.