After its dim third-quarter earnings report on Nov. 2, Moderna (MRNA 1.69%) saw its shares crash by more than 12% before recovering. Still, the stock is down by 60% this year, and it's clear that investors continue to have doubts about prospects for the once-vaunted biotech.

But there's more than one reason to believe Moderna may yet have a bright future ahead, provided that you're willing to hold it over the next few years. Let's examine how its strategic plans and favorable stock valuation might make it a great performer for those with a little patience.

Forget the COVID vaccines

Most people are familiar with Moderna thanks to its coronavirus vaccines. It's going to continue making those jabs, but in case it wasn't obvious, peak sales of those vaccinations are in the past and won't be returning.

The company anticipates residual sales of Spikevax to reach $6 billion in 2023, which likely will fall further to $4 billion in 2024. Compared to its haul in excess of $19 billion last year, that sum isn't much. So far, its prior hopes for the seasonal market for updated booster shots being enough to sustain the top line have not been borne out.

The next driver of fresh revenue will likely be its respiratory syncytial virus (RSV) vaccine for older adults, which it expects to launch in 2024, assuming regulators approve it. Despite its performance characteristics, which management describes as the best in its class, it will have some competition. Pfizer brought in $375 million in the third quarter with its RSV shot, and GSK's version is selling even more. Grabbing market share from those two juggernauts will be difficult, so it is unlikely that the vaccine will have a blowout debut.

Moderna's prospects beyond RSV are even more important to the bull thesis, however. The company's pipeline has as many as 15 new or updated medicines it could commercialize within the next five years. Management has been diligently funneling its coronavirus vaccine windfalls into research and development (R&D) to provision for its future. There should be additional R&D investment of $25 billion between 2024 and 2028.

Among the notable programs set to advance are its combination vaccine for COVID-19, influenza, and RSV, which could easily become a seasonal staple for public health organizations worldwide as a result of its convenience.

In its oncology segment, it also has three vaccines designed to treat cancers like melanoma and non-small cell lung cancer in conjunction with other medicines. And most of its rare-disease portfolio is in early to mid-stage clinical testing right now.

By 2028, Moderna could have a base of strongly recurring sales from its seasonal prophylactic vaccines, as well as significant revenue from its therapeutic vaccines for oncology and a few rare diseases. By then, its top line might not be bigger than it was in 2022, but it could still grow a huge amount from where it is today, beefing up its share price in the process.

It probably won't be a bargain forever

Moderna's next couple of years are more likely to be transitional than impressive. It's no surprise that the market is showing its disfavor for the stock. Its shares might yet drop further as it doesn't particularly have anything coming up that would make the market swoon in expectation of massive new revenue. There is also no guarantee that 100% of its ongoing clinical trials will succeed.

But for farsighted investors, the stock is currently at an attractive entry point. Right now, its price-to-sales (P/S) ratio is 2.9. For reference, in the third quarter of 2019, well before its blockbuster coronavirus jab was even on the radar (and in fact before it even had any products on the market), its P/S multiple was 56. At the end of 2020, it was 686.

So it is safe to say that the pandemic-era hype that drove its valuation skyward is now fully deflated. That means the risk of a rapid deflation of its shares is far lower than it was just last year.

If you can stomach the idea of its shares getting even cheaper as the remaining scale-down of its coronavirus revenue plays out through 2024, Moderna stock is a no-brainer buy at the moment. It's rare to find a biotech with a proven development platform, a battle-tested and visionary management team, and a world-class commercial organization. It's even rarer to find such a company priced cheaply. Just don't expect success to arrive overnight.