Moderna mRNA RSV Vaccine for Adults Returns Positive Phase 3 Results

Positive results from a phase 2-3 trial investigating the safety and efficacy of an mRNA-based respiratory syncytial virus (RSV) vaccine from Moderna were recently published in The New England Journal of Medicine, the pharmaceutical company announced.¹

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The randomized, double-blind, placebo-controlled study included 35 541 adults 60 years of age or older who received either a single dose of the vaccine or a placebo.² Investigators found that the vaccine had an efficacy of 83.7% against RSV-associated lower respiratory tract disease with at least 2 signs or symptoms and 82.4% against the disease with at least 3 signs or symptoms.²

The investigational vaccine also demonstrated an efficacy of 68.4% against RSV-associated acute respiratory disease. Protection was observed against both RSV A and B subtypes and was mostly consistent across subgroups.²

Local and systemic adverse reactions were more common among participants in the active vaccine group compared to the placebo group, although most were transient and mild to moderate in severity. In both groups, 2.8% of participants experienced severe adverse events.

The vaccine, called mRNA-1345, has a single mRNA sequence encoding for a stabilized prefusion F glycoprotein and uses the same lipid nanoparticles as Moderna’s COVID-19 vaccines. It is the only RSV vaccine based on an mRNA technology platform.

"Respiratory diseases are a major public health priority given they have a significant health impact and are a leading cause of hospitalization,” Stéphane Bancel, Moderna's CEO, said in a release.³ “For these reasons, in addition to our mRNA-1345 RSV vaccine candidate, we are committed to developing a portfolio of respiratory mRNA vaccines to target the most significant viruses causing respiratory disease, including COVID-19, influenza, and human metapneumovirus."³

RSV is a highly contagious virus that impacts people of all ages, but it can lead to more severe disease in older adults and younger children. It causes 60 000 to 160 000 hospitalizations and 6000 to 10 000 deaths in older adults each year in the United States.

Moderna said that it is currently preparing for an expected marketing launch of the vaccine in 2024. The company also said that it has submitted applications for mRNA-1345 to regulators across the globe. If approved, it will be the only ready-to-use RSV vaccine available in single-dose prefilled syringes.

References

1. Moderna Announces New England Journal of Medicine publication of pivotal phase 3 clinical safety and efficacy data for MRNA-1345, the company's investigational respiratory syncytial virus (RSV) vaccine. News Release. Moderna. December 14, 2023. Accessed January 3, 2024. https://investors.modernatx.com/news/news-details/2023/Moderna-Announces-New-England-Journal-of-Medicine-Publication-of-Pivotal-Phase-3-Clinical-Safety-and-Efficacy-Data-For-MRNA-1345-The-Companys-Investigational-Respiratory-Syncytial-Virus-RSV-Vaccine/default.aspx

2. Wilson E, Goswami J, Baqui AH, et al. Efficacy and safety of an mrna-based RSV pref vaccine in older adults. N Engl J Med. 2023;389(24):2233-2244. doi:10.1056/nejmoa2307079

3. Moderna announces mRNA-1345, an investigational respiratory syncytial virus (RSV) vaccine, has met primary efficacy endpoints in phase 3 trial in older adults. . News Release. Moderna. January 17, 2023. Accessed January 3, 2024. https://news.modernatx.com/news/news-details/2023/Moderna-Announces-mRNA-1345-an-Investigational-Respiratory-Syncytial-Virus-RSV-Vaccine-Has-Met-Primary-Efficacy-Endpoints-in-Phase-3-Trial-in-Older-Adults/default.aspx