Moderna’s New COVID Vaccine Gets FDA Green Light; Yet Retail Stays Cautious

Investor sentiment on Moderna turned bearish over the weekend despite FDA approval of its new COVID-19 vaccine, mNEXSPIKE, which showed higher efficacy and a favorable safety profile.

Investor sentiment toward Moderna Inc. turned sour during the weekend, despite obtaining FDA authorization for its newest COVID-19 vaccine, mNEXSPIKE (mRNA-1283). 

Moderna shares ended Friday down 1.4% at $26.56, before edging up slightly to $26.58 in after-hours trading.

The vaccine targets adults 65 and older, as well as individuals aged 12-64 with CDC-defined risk factors.

On May 31, Moderna said that mNEXSPIKE received FDA approval as their third COVID-19 vaccine after Phase 3 clinical trials showed it yielded 9.3% higher efficacy than the original Spikevax (mRNA-1273). 

According to the company, the vaccine demonstrated a favorable safety profile by reporting fewer local reactions.

Meanwhile, the Centers for Disease Control and Prevention (CDC) revised its COVID-19 vaccine guidance on Thursday to endorse shared clinical decision-making for vaccinating children ages six months to 17 years. 

Moderna’s mNEXSPIKE will be available in the U.S. during the 2025-2026 respiratory virus season, in addition to Spikevax and its RSV vaccine mRESVIA. 

Regulatory review for mRNA-1283 is also underway in multiple other markets.

The mNEXSPIKE vaccine targets severe COVID-19 complications in high-risk populations, but Moderna warns that it may not fully protect all recipients. 

Patients have reported injection site pain, fatigue, headache, and infrequent myocarditis, mostly in young males, as side effects.

On Stocktwits, retail sentiment was ‘bearish’ amid ‘normal’ message volume.

One user said the recent FDA approval of Moderna’s vaccine might be short-lived and speculated about possible investigations involving FDA employees. 

Another user predicted the stock could fall back to around $10.

The stock has declined 36.8% in 2025, underperforming the S&P 500’s 0.7% gain.

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