Moderna (MRNA 1.69%) stock soared during the pandemic as investors bet on the company's coronavirus vaccine candidate. Since then, the biotech launched a vaccine, followed by updated boosters, and generated billions of dollars in earnings. But the stock-price performance has stumbled in the post-pandemic world, and investors are worried about Moderna's reliance on its only product.

The company may not be a one-product company for long, though. It may not even be a two-product company for long. The company has big plans for the next several years and has set out a roadmap to reach its goals.

Moderna offered investors more details about its projects and prospects this week during its annual R&D Day. If you're worried about Moderna, one number may completely change your mind.

On-time for vaccination season

First, here's a quick summary of Moderna's current situation. The company is set to launch its updated coronavirus vaccine, right on time for the fall vaccination season. The U.S. Food and Drug Administration gave Moderna and rival Pfizer the green light, and vaccinations may start as soon as this week.

This season represents a bit of a change for vaccine makers as the market shifts to a private one -- meaning companies are starting to sell doses directly to healthcare providers instead of governments. In such a market, they might sell fewer doses, but prices could be considerably higher. For example, Moderna sold its vaccine to the government for about $26 -- and it plans to sell to the private market for $129, according to Reuters.

Moderna expects vaccine sales to total about $6 billion to $8 billion this year. This means the vaccine still is a blockbuster product, but sales are a far cry from last year's $18 billion. And that's what has disappointed investors.

Now let's get to the number that should change your opinion about this biotech player. And that number is "30 billion."

Yes, Moderna's coronavirus vaccine revenue is on the decline, but the company's overall revenue may far surpass that of the vaccine just a few years from now. If all goes according to plan, Moderna predicts revenue of as much as $30 billion, thanks to its respiratory vaccines platform, as well as its oncology and rare and latent disease programs.

$15 billion in 2027

Specifically, Moderna says the respiratory vaccine platform should bring in $8 billion to $15 billion in 2027. And the oncology and rare and latent disease platforms should add $10 billion to $15 billion to sales five years after launch. The company aims to launch as many as 15 new products within the coming five years, so this predicted sales growth could be right around the corner.

Moderna recently completed regulatory submissions worldwide for its respiratory syncytial virus (RSV) vaccine candidate and expects a decision in the U.S. in April. It's also studying several candidates in phase 3, such as a personalized cancer vaccine for melanoma and a vaccine to prevent latent virus cytomegalovirus. These could be next to cross the finish line.

A smaller part of the revenue picture

Moving forward, the coronavirus vaccine will make up a small part of the overall revenue picture at Moderna. And that's a good thing. It means the company no longer will depend on one product -- and specifically one linked to a pandemic -- and instead will rely on a broad range of products. This reduces risk for Moderna and its investors.

At the same time, if all goes smoothly, the company may greatly surpass its pandemic revenue. All of this in a period of just a few years.

What does this mean for you as an investor? It means Moderna looks like a steal right now, trading at only 8x forward earnings estimates. That's because the company's earnings could grow considerably later this decade. Right now may be the perfect time to scoop up shares of this biotech innovator and sit back and wait.