Moderna (MRNA -1.75%) generated revenue of roughly $60 million in 2019. The company will post total revenue measured in the hundreds of millions of dollars for 2020. But the big bucks begin rolling in this year.

Well over 600 million doses of Moderna's COVID-19 vaccine mRNA-1273 will be sold in 2021. Based on its current supply agreements, the company should make around $11.7 billion. 

There's been considerable uncertainty, though, about what kind of recurring revenue Moderna could make from mRNA-1273 after this year. But investors now have a reason to be more optimistic about the company's prospects. Nine words uttered by Moderna's CEO Stephane Bancel last week could mean billions for the biotech.

Vaccine vials forming a dollar sign

Image source: Getty Images.

A strong financial statement

A couple of weeks ago, Bancel said that the "nightmare scenario" where mRNA-1273 provided protection for only a few months was now "out of the window." He added that the slow decay of antibodies generated through the vaccine indicates that the duration of protection of mRNA-1273 could be up to two years.

That news was certainly encouraging for people across the world and for investors. Two years of immunity would mean that Moderna could at least see substantial revenue from its vaccine every other year.

But in an interview with CNBC last week, Bancel gave investors even more reason to be excited. He stated, "I think this will become a market like flu." The flu, of course, is seasonal, with vaccines administered on a yearly basis.

The financial implications for Moderna if Bancel's statement is correct are enormous. It could mean that the biotech will be able to make close to half as much money on an annual basis as it will make in 2021, assuming an annual booster shot requires only one dose compared to the initial two-dose regimen.  

Is Bancel right?

There's still a multibillion-dollar question, though: Is Stephane Bancel's view correct that the COVID-19 vaccine market will be like the flu vaccine market? The answer is that we still don't know for sure.

Moderna's expectations of annual booster shots hinge on extrapolations of the future rate of decay for antibodies produced by mRNA-1273 based on the past rate. That's a reasonable approach, but it's still only an estimation.

The only way to be certain about the duration of immunity provided by mRNA-1273 is to wait and watch the individuals who have received the initial two-dose regimen. Further clinical studies evaluating booster shots will also be needed.

Moderna plans to kick off such a study of a booster dose of mRNA-1273 in July. The biotech's chief medical officer Tal Zaks stated at the J.P. Morgan Healthcare Conference last week, "To the degree that you need a booster shot, we'll make a data-based recommendation, and that will require us getting the data."

Other dynamics at work

If Moderna can count on raking in billions of dollars from mRNA-1273 every year, the biotech stock could have more room to run after its huge gain in 2020. However, there are other dynamics at work in addition to the duration of immunity provided by Moderna's COVID-19 vaccine.

Perhaps most importantly, the competitive landscape could change significantly. Increased overall supply of coronavirus vaccines in the future could exert downward pressure on the price that Moderna is able to charge for mRNA-1273. Single-dose COVID-19 vaccines could be on the way. So could vaccines that provide mucosal immunity (immune system responses that occur in mucosal membranes in the eyes, nose, and elsewhere). 

Still, if the nine words uttered by Stephane Bancel last week prove to be true, Moderna's future could be a bright one.