The U.S. now has a third coronavirus vaccine authorized for use. Johnson & Johnson's (NYSE:JNJ) vaccine, developed by its subsidiary Janssen, received Emergency Use Authorization (EUA) from the FDA on Saturday. This followed a unanimous vote by the regulator's vaccines and related biological products advisory committee that it do so.

In contrast to the two shots required for both of the other FDA-authorized coronavirus vaccines -- Moderna's (NASDAQ:MRNA) mRNA-1273 and Pfizer (NYSE:PFE) and BioNTech's (NASDAQ:BNTX) BNT162b2 -- Johnson & Johnson's is a one-shot inoculation. 

Gloved hand filling a syringe from a vial.

Image source: Getty Images.

It also has relatively less burdensome storage requirements, as it can be kept for as long as three months in standard refrigeration temperatures of 36 to 46 degrees Fahrenheit.

The Johnson & Johnson vaccine demonstrated notably lower efficacy (72%) in late-stage testing compared the 95% or so of its two peers. However, 72% is still considered unusually high by vaccine development standards, plus Johnson & Johnson's was shown to be 100% efficacious in preventing hospitalization and death. 

The Moderna and Pfizer/BioNTech shots were authorized in December and so far have been administered to nearly 15% of the U.S. population So it's likely that Johnson & Johnson's jab won't lap past them, no matter its advantages. It will, however, help push the inoculation rate up quickly.

Investors should be aware that Johnson & Johnson won't be making money from the vaccine during the pandemic. As it reiterated in the press release trumpeting the EUA, it will provide the jab "on a not-for-profit basis for emergency pandemic use."

The company added that it has already started to ship the vaccine, with the goal of delivering enough to inoculate over 20 million people in this country by the end of March. 100 million doses should by shipped by the end of June.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.