It's possible that two jabs of Moderna's (MRNA 0.89%) recently authorized coronavirus vaccine will be sufficient for long-term protection against the global health scourge. On Thursday, the company's CEO Stephane Bancel said at a healthcare industry event that this is a likely possibility, due to the durability of the antibodies the vaccine produces.

"The antibody decay generated by the vaccine in humans goes down very slowly," he said in remarks quoted by Reuters. "We believe there will be protection potentially for a couple of years." He didn't offer a more specific time forecast.

He did add that, "The nightmare scenario that was described in the media in the spring with a vaccine only working a month or two is, I think, out of the window."

Man receiving a vaccination shot.

Image source: Getty Images.

If Bancel's estimation is accurate, it would make mRNA-1273 -- and perhaps Pfizer and BioNTech's BNT162b2, plus other vaccines that utilize similar messenger RNA technology -- a far more powerful weapon against the coronavirus than previously imagined. The need for a strong and effective vaccine is particularly acute now, given that cases and fatalities continue to rise around the globe and a new strain seems to be even more contagious.

Bancel also commented about that strain, claiming that Moderna was on the cusp of proving that mRNA-1273 can be effective against that, too. Further details weren't provided.

At the moment, mRNA-1273 is authorized for use in the U.S., the U.K, Israel, and throughout the 27-member European Union. More authorizations by major healthcare regulators are almost certain to follow, keeping Moderna at or near the front of the coronavirus vaccine "race."

Despite Bancel's very hopeful pronouncements, Moderna didn't have a good day on the exchange Thursday. It fell by 1%, against the almost 1.5% gain of the S&P 500 index.