Moderna’s RSV Vaccine Gets FDA Nod For Younger At-Risk Adults: Retail Stays Guarded Amid RFK Jr’s Immunization Shake-Up

Moderna, Inc. (MRNA) announced late Thursday that the U.S. Food and Drug Administration (FDA) has approved its respiratory syncytial virus (RSV) vaccine for adults aged 18-59 with underlying health conditions.

The vaccine, mRESVIA (mRNA-1345), is currently approved for adults aged 60 and older.

The expanded indication is based on Phase 3 data showing strong immune responses in younger at-risk adults, with neutralizing antibody levels comparable to those seen in older adults.

The vaccine was generally well tolerated, with the most common side effects including injection site pain, fatigue, headache, and muscle or joint pain.

According to Moderna, RSV risk in adults under 60 years of age is often overlooked, but over one-third of adults in this age group have at least one chronic condition that raises their risk for severe disease, with hospitalization rates similar to or exceeding those seen in older populations.

Moderna said it plans to make mRESVIA available for both younger and older adults in the U.S. ahead of the 2025-2026 respiratory virus season.

The announcement came after 7 p.m. ET on Thursday, after the stock ended the regular session 1.4% lower and extended losses in after-hours trading.

On Stocktwits, sentiment for MRNA remained ‘neutral’, although the score increased by a few points.

“I think tomorrow be will be up pretty solid. Two approvals in two weeks, that's insane for a 10b market cap company,” said one bullish watcher.

However, some trepidation was visible due to regulatory overhauls under the Trump administration.

On Thursday, Health Secretary Robert F. Kennedy Jr. appointed eight new members to the Advisory Immunization Committee, including vaccine opponents, two days after abruptly removing all 17 prior members.

Bloomberg News also reported that Moderna is in talks with large drugmakers and financial firms to get funding for some late-stage vaccine trials as it navigates significant changes to vaccine policy under Kennedy Jr. and declining sales of its COVID-19 vaccine.

Moderna stock has lost more than 35% this year.

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