Moderna Approved for Phase 3 Respiratory Syncytial Virus (RSV) Vaccine Trial

Respiratory syncytial virus (RSV) causes a severe disease burden in older adults and young children, but there is currently no approved RSV vaccine.

Today, Moderna, Inc. announced the Data and Safety Monitoring Board (DSMB) has endorsed the start of the phase 3 clinical trial for their RSV vaccine candidate. The vaccine, mRNA-1345, uses Moderna’s messenger RNA technology to optimize protein and codon sequences.

The DSMB endorsement comes after an independent review of the mRNA-1345 phase 2 trial, in which the selected dose had a sufficient safety profile in older adults.

The US Food and Drug Administration (FDA) granted a Fast Track designation to mRNA-1345 for adults 60 years and older. With approximately 177000 hospitalizations and 14000 deaths in older Americans each year, RSV accounts for a significant unmet medical burden.

RSV typically causes cold-like symptoms, with most infected persons recovering in 1-2 weeks. However, younger children and older adults are especially susceptible to RSV-induced pneumonia and respiratory distress.

"RSV is one of the most widespread respiratory viruses, causing severe disease and hospitalization in older adults, and yet there is no vaccine available on the market. We believe that our vaccine candidate against RSV has the potential to protect against over 1 million infections globally each year, improving quality of life for those at high-risk of becoming infected and reducing the burden on health care systems,” said Stéphane Bancel, the Chief Executive Officer of Moderna.

mRNA-1345 encodes the prefusion F glycoprotein to induce a higher neutralizing antibody response than is found in the postfusion state. mRNA-1345 contains the same lipid nanoparticle (LNP) as Moderna’s COVID-19 vaccine.

The primary goal of the phase 3 study is to establish whether mRNA-1345 is safe and effective against RSV. The vaccine will be tested in adults 60 years and older. Moderna is anticipating to recruit 34000 participants from myriad countries for the RSV vaccine trial, and those interested in joining the trial can learn more about enrollment criteria here.

Also in development is a single-dose vaccine that serves as a combined influenza and COVID-19 booster. Moderna noted in preclinical studies that seasonal flu, RSV, and COVID-19 booster vaccines can all be combined in a single vaccine that boosts immunity to 6 antigens.