Moderna has announced positive results from an early-stage clinical trial of its experimental messenger RNA-based combination vaccine designed to protect against both COVID-19 and influenza. The Phase 1/2 study demonstrated that the vaccine candidate generated immune responses against both viruses that were similar to or stronger than those produced by individual vaccines.
Promising Immune Response Data
According to the company, the combination vaccine spurred similar or stronger immune responses against all four influenza strains compared to standalone flu vaccines. When measured against Moderna's Spikevax COVID-19 booster, the combo shot also showed comparable effectiveness in older adults, who are typically more vulnerable to both diseases.
The trial compared the combination candidate against GSK's Fluarix in adults aged 50-64 and Sanofi's Fluzone HD in adults aged 65-79. Most side effects were reported to be mild in severity, suggesting a favorable safety profile consistent with the company's other mRNA vaccines.
Strategic Importance for Respiratory Disease Prevention
This development represents a significant step in Moderna's respiratory vaccine strategy, which focuses on simplifying protection against multiple seasonal respiratory illnesses. Currently, the Centers for Disease Control and Prevention (CDC) recommends that older adults, particularly those who are immunocompromised, receive separate vaccinations for flu, COVID-19, and respiratory syncytial virus (RSV).
"A combination shot, such as the one Moderna is developing, could make the process of annual vaccination easier," noted a company spokesperson. This approach could potentially increase vaccination rates by reducing the number of shots needed and simplifying the vaccination schedule.
Broader Pipeline Progress
The combination vaccine news comes amid several positive developments across Moderna's respiratory vaccine portfolio. The company recently announced that its standalone flu vaccine candidate, mRNA-1010, met all primary endpoints in a Phase 3 trial, demonstrating higher immune responses across all four influenza strains compared to a licensed comparator.
In the Phase 3 safety and immunogenicity trial (P303), mRNA-1010 showed higher hemagglutination inhibition (HAI) geometric mean titers and seroconversion rates for all four strains (A/H1N1, A/H3N2, influenza B/Yamagata, B/Victoria) compared to Fluarix. A separate Phase 1/2 head-to-head study also showed higher HAI titers against three strains and comparable titers against the fourth when compared to Fluzone HD.
Advancing Toward Late-Stage Development
With these positive early results, Moderna plans to advance the COVID-19/flu combination vaccine to Phase 3 clinical trials later this year. The company is targeting regulatory approval in 2025, which would position it as one of the first combination respiratory vaccines to reach the market.
"Our mRNA platform is working. With today's positive Phase 3 flu results, along with previous results in COVID and RSV, we are now three for three on advancing respiratory disease programs to positive Phase 3 data," said Stéphane Bancel, Chief Executive Officer of Moderna.
Market Outlook and Commercial Potential
Moderna has previously predicted that its respiratory products would generate sales between $8 billion and $15 billion by 2027. The company views the COVID-19 booster and seasonal influenza shot markets as similarly sized, at least in the United States.
However, analysts note that both Moderna and rival Pfizer are currently dealing with declining sales of their COVID-19 vaccines. Despite recent FDA clearance of updated shots, vaccination rates have remained low even as hospitalizations and deaths increased during the summer months.
Michael Yee, an analyst at Jefferies, wrote that Moderna's COVID sales forecasts will continue "to be debated given skepticism by Wall Street due to low COVID infections and low vaccination rates."
Broader Combination Vaccine Strategy
Beyond the COVID-19/flu combination, Moderna is advancing several other combination vaccines, including:
- Flu/RSV (mRNA-1045)
- Flu/COVID-19/RSV (mRNA-1230)
- Flu/COVID-19 with next-generation formulations (mRNA-1083)
The company has completed enrollment in Phase 1/2 trials for these candidates and expects to provide an investor update in the fourth quarter of this year.
As part of its broader respiratory franchise strategy, Moderna is targeting an approximately $30 billion annual market, comprised of approximately $15 billion for COVID-19, $10 billion for RSV, and $6 billion for influenza vaccines.
The development of effective combination vaccines could significantly impact public health by increasing vaccination coverage through improved convenience and compliance, potentially reducing the burden of multiple respiratory diseases that typically surge during winter months.
