Moderna (MRNA -2.21%) is a healthcare business in transition. Expectations are lower this year as the government isn't going to be loading up on the company's COVID-19 vaccine anymore.

That doesn't mean sales will evaporate, but investors do need to brace for a new reality for the business. Year to date, Moderna's shares have fallen 22% even as the S&P 500 has shown signs of life, rising 3%.

Has Moderna become a bad-news buy, or are shares of the healthcare stock likely to decline even further?

Sales dropped nearly 30% last quarter

Moderna had an exceptional year in 2022, with revenue topping $19.3 billion, for a year-over-year increase of 4.3%. But the bigger story is that for the last three months of the year, revenue nosedived by 29% to just under $5.1 billion. The business is going to have an uphill battle in replacing COVID-19 revenue as concerns about the pandemic subside. And that is likely too high of a mountain to climb in the short term.

While vaccine sales aren't going to go to zero this year, the company is expecting around $5 billion, which would be a mammoth decline for the business. And to make matters worse, the company is likely going to be unprofitable again.

Costs to top $6 billion this year

Over the past two years, Moderna netted profits of more than $20 billion combined. The company's vaccines effectively sold themselves thanks to the government, so there wasn't a need for significant promotional activities. As a result, Moderna looked like a rockstar with an incredible profit margin of 43% last year.

Posting a profit won't be nearly as easy in the future. The company projects that its costs will be $6 billion this year, which is less than its revenue projection from COVID-19 products. That sets up the company for a significant shortfall, and what's likely to be a unprofitable year.

There are many questions marks relating to the business right now, including how much revenue is a reasonable amount to expect from the business and whether it will be profitable again in the future.

The pipeline isn't bare, but is it enough?

Moderna has been working on new products that it hopes to bring to market to help offset the loss in COVID-19 revenue. Its vaccine candidate for the respiratory syncytial virus (RSV) is one of its most promising, and the market for an adult RSV could be worth up to $10 billion. But it'll be fighting for market share along with Pfizer and GSK, which both have RSV vaccines of their own in the works.

The company also has a promising personal cancer vaccine candidate that it is working on with Merck that, if it's effective in treating multiple types of tumors, could generate up to $5 billion in annual revenue. The companies would split the profits on the vaccine. Then there's also its potential vaccine for the cytomegalovirus, which is in late-stage trials and that Moderna thinks could bring in another $5 billion in revenue at its peak.

Bit by bit, you can start to see how Moderna might be able to get back to growing and being able to potentially replace its lost COVID-19 revenue, especially if it were to acquire a company to help accelerate its growth. Moderna reported just under $10 billion in cash and investments as of the end of 2022, so it does have the resources to make a big move should it decide to do so.

Should you buy Moderna's stock right now?

Moderna does have potential in the long run to be a good growth stock again. But clinical trials are never a guarantee, and while its pipeline does look encouraging, investors need to brace for the possibility that some of those vaccine candidates may not pan out and be as successful as the company is hoping they will. Plus there's the issue of profitability, which also may not be a sure thing -- the company will have to spend significant resources to not just develop the products, but to also sell and promote them.

At its current price, which is not even a 52-week low, and is three times a revenue number that is going to nosedive in the months ahead, the stock is too expensive for the risks and uncertainty ahead. As the year goes on and reality starts to set in for investors that the growth days may be over for a while, I would expect to see the stock decline further. And until that happens, investors are better off avoiding it.