Late-stage trials show efficacy of Moderna’s RSV vaccine in older adults

On January 17, Moderna announced that data from a late-stage clinical trial for the company’s experimental messenger RNA (mRNA) vaccine for respiratory syncytial virus (RSV) was 83.7 percent effective at preventing at least two symptoms, such as cough and fever, in adults 60 and older.

“RSV significantly affects the health of older and high-risk adults, particularly those with comorbidities,” Abdullah Baqui, a principal investigator for the study sites in Bangladesh and professor at Johns Hopkins Bloomberg School of Public Health, said in a statement. “This trial will help to understand the role of severe acute respiratory infections in older adult populations and inform the future implementation of vaccines in adults in lower-resource areas.”

[Related: Is it flu or RSV? It can be tough to tell.]

The study was conducted in roughly 37,000 participants age 60 and older and the data analysis was performed after 64 of the participants contracted the virus. Moderna plans to release the full data at an upcoming medical meeting and will seek approval from the Food and Drug Administration (FDA) during the first half of 2023.

“Today’s results represent an important step forward in preventing lower respiratory disease due to RSV in adults 60 years of age and older. These data are encouraging, and represent the second demonstration of positive phase 3 trial results from our mRNA infectious disease vaccine platform after, Spikevax, our COVID-19 vaccine. We look forward to publishing the full data set and sharing the results at an upcoming infectious disease medical conference,” said Stéphane Bancel, Moderna’s Chief Executive Officer, in a statement.

Currently, there is no vaccine to prevent RSV infection and Moderna, Pfizer, and GSK are working to get their vaccines out to the public. In 2022, Pfizer and GSK filed applications for regulatory approval in the United States and late-stage trial results found that Pfizer’s RSV vaccine was 66.7 percent effective in preventing two or more symptoms.

[Related: How our pandemic toolkit fought the many viruses of 2022.]

In Europe, an antibody treatment called nirsevimab from Sanofi and AstraZeneca gained the European Commission’s marketing authorization to prevent the virus in newborns and infants. This treatment is under review by the FDA for use in the US.

While RSV produces symptoms similar to a cold, it can be fatal for young children and older adults. According to the CDC, about 60,000 to 120,000 older adults are hospitalized and between 6,000 to 10,000 die due to RSV infection every year.

Cases of RSV began appearing earlier than usual during the 2022-2023 RSV season, but cases have ticked downward after peaking in November 2022. RSV surged in the US and Europe this alongside the flu and COVID-19 as part of a “tripledemic” that has been straining hospitals and has even caused shortages of children’s pain relievers and fever reducers.