Moderna says new RSV vaccine 84% effective in older adults

A vaccine against the respiratory syncytial virus (RSV) being developed by Moderna is 83.7% effective at preventing respiratory disease in older adults, the biotechnology company announced on Tuesday.

What is RSV?

RSV is a respiratory virus that usually causes mild, cold-like symptoms, but can cause serious complications in infants and older adults. According to the US CDC, 60,000-120,000 older adults are hospitalized and 6,000-10,000 older adults die every year due to RSV.

In April, a study found that RSV was keeping children in the hospital twice as long as COVID-19. They also needed oxygen masks and intubation more than those with COVID-19.

Last week, the Health Ministry reported that, as of January 7, some 3,260 Israelis had been hospitalized due to RSV since October.

For the Phase 3 ConquerRSV trial, Moderna conducted a randomized, double-blind, placebo-controlled study among about 37,000 adults aged 60 and older in 22 countries, including the US. The study defined disease caused by RSV as including two or more symptoms.

The study found 64 cases of RSV-caused disease including at least two symptoms among participants, 55 of which occurred in the placebo group and nine of which occurred among the group that received the vaccine.

No safety concerns were found with Moderna's RSV vaccine

No safety concerns were identified with the vaccine. Most adverse reactions to the vaccine were mild or moderate, with the most commonly reported reaction being injection site pain, fatigue, headache, muscle pain and joint stiffness.

The rate of severe adverse reactions recorded in the study was 4% for those who received the vaccine and 2.8% for those who received the placebo. As the study is ongoing, an updated analysis of safety and tolerability will be provided when the vaccine is submitted for regulatory approval.

Moderna's mRNA-1345 RSV vaccine uses lipid nanoparticles (bubbles made up of fatty acids used to deliver the mRNA into cells) that the company's COVID-19 vaccine uses.

"Today's results represent an important step forward in preventing lower respiratory disease due to RSV in adults 60 years of age and older," CEO Stéphane Bancel said. "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.

"Respiratory diseases are a major public health priority given they have a significant health impact and are a leading cause of hospitalization. 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."

Moderna stated that it intends to submit the vaccine for regulatory approval in the first half of this year.

"RSV significantly affects the health of older and high-risk adults, particularly those with comorbidities," said Abdullah Baqui, a principal investigator for the study sites in Bangladesh and professor at the Department of International Health and director of the International Center for Maternal and Newborn Health at Johns Hopkins Bloomberg School of Public Health at Johns Hopkins University. "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."

The findings of the phase 3 trial will be submitted for peer-reviewed publication and presented at an upcoming scientific meeting.

Moderna is also conducting four other RSV vaccine trials, including one for a vaccine for children and combination clinical trials. The company is also conducting trials for a combination vaccine targeting SARS-CoV-2, influenza and RSV all at once and another targeting influenza and RSV.