TORONTO (AP) — Canada is getting a fourth vaccine to prevent COVID-19 as the country's health regulator cleared a Johnson & Johnson shot that works with just one dose instead of two, a person familiar with the matter told The Associated Press.

Health experts are eager for a one-and-done option to help speed vaccination. Canada has also approved vaccines from Pfizer, Moderna and AstraZeneca. The official confirmed the approval on condition of anonymity as they were not authorized to speak publicly ahead of the Health Canada announcement.

Like many countries, Canada does not have domestic production and has struggled with an immediate shortage of vaccines.

Canada has pre-purchased 10 million Johnson & Johnson doses, with options to buy another 28 million.