FDA Approves Moderna's RSV Vaccine

The US Food and Drug Administration (FDA) has approved Moderna's mResvia, a vaccine designed to protect against respiratory syncytial virus (RSV) in adults aged 60 and older. The vaccine demonstrated 79% effectiveness in preventing at least two symptoms of RSV, such as cough and fever. Moderna plans to distribute mResvia by fall 2024. 

Moderna's mResvia is the third RSV vaccine to receive FDA approval, following GSK's Arexvy and Pfizer's Abrysvo last year. The US Centers for Disease Control and Prevention (CDC) will convene next month to provide usage recommendations, with Moderna aiming to launch the vaccine for the fall immunization season in the United States.

RSV is a common respiratory virus that typically causes mild cold-like symptoms but can lead to severe illness and even death, especially in infants and older adults with chronic health conditions. Moderna's entry into this market is expected to enhance accessibility and competition, potentially improving public health outcomes, according to BioPharma Dive. 

In Mexico, the National Committee for Epidemiological Surveillance reported a significant increase in respiratory virus cases between epidemiological weeks 40 and 45 of 2023, with RSV accounting for 63.1% of confirmed cases. Children under 10 years old were most affected, with the highest numbers of cases recorded in Mexico City and the State of Mexico.

Moderna's mResvia, based on messenger RNA technology, stimulates the body to recognize the prefusion F protein of RSV, similar to its competitors. Stéphane Bancel, CEO, Moderna, highlights that mResvia includes a prefilled syringe format, which reduces the burden on pharmacies compared to more complex shots from competitors. "Our prefilled syringe presentation is ready to use straight out of the box," says Bancel.

Demand for RSV vaccines typically peaks in late summer to fall, aligning with the virus's seasonal pattern. Moderna projects the total RSV vaccine market to grow to between US$6 billion and US$8 billion annually.

Moderna anticipates about US$4 billion in net sales for 2024 from its COVID-19 and RSV vaccines. In trials, mResvia showed about 84% effectiveness against RSV-related disease with two or more symptoms, similar to GSK's Arexvy. Pfizer's Abrysvo appeared slightly less effective, though direct comparisons are not available.

All three vaccines' efficacy wanes over time, with mResvia's effectiveness decreasing to about 63% after 8.6 months. Despite this, all three vaccines are generally safe, with common side effects including fatigue, headache, and injection site pain.