Moderna (NASDAQ:MRNA) took a hit Tuesday as Barclays downgraded the stock from Overweight to Equal Weight, citing policy risks, fewer clinical catalysts, and broader economic uncertainties that could limit its upside. Along with the downgrade, the firm lowered its price target to $45 following Moderna's Q4 2024 earnings update.

• Warning! GuruFocus has detected 6 Warning Signs with MRNA.

Barclays still acknowledges Moderna's RNA platform as a differentiator, but analysts don't see much room for growth in the near term. The biggest concerns? Vaccine policy risks in the U.S. and a lack of major clinical milestones on the horizon.

One notable issue is Moderna's Phase 3 norovirus vaccine trial (mRNA-1403), which was placed on clinical hold after a participant developed Guillain-Barre syndrome (GBS). While that sounds concerning, Barclays notes that the trial remains on track, as Northern Hemisphere enrollment is complete and preparations for the Southern Hemisphere's second season are ongoing. Moderna's management believes the GBS case is unrelated and doesn't expect it to derail the study.

Financially, things aren't looking great. SpikeVax sales in Q4 totaled $923 million, missing Barclays' forecast of $1.087 billion. Full-year 2024 product revenue dropped 53% year-over-year to $3.1 billion.

For 2025, Moderna reaffirmed its revenue guidance of $1.5 billion to $2.5 billion, but only expects $200 million in sales during the first half of the year, mainly due to the seasonal nature of the respiratory vaccine market.

Even with cost-cutting efforts, Barclays remains skeptical. The firm points out that Moderna doesn't expect to break even on cash flow until 2028, and operating expenses remain high. Given the current challenges, Barclays is taking a cautious stance on the stock, saying it's best to step to the sideline for now.