Moderna has announced phase 3 data for its mRNA-1083 combination COVID/flu vaccine elicited a higher immune response against two influenza A strains and one B strain when compared to the widely used flu vaccines from GSK and Sanofi.

The phase 3 results support the findings from the phase 2 studies I reported late in 2023. Also, Pfizer and BioNTech are in late clinical studies for a similar mRNA-based combination COVID/flu vaccine — I’ll report on this when they announce results publicly.

Although the results of the phase 3 studies for mRNA-1083 have not been published yet in a peer-reviewed journal, Moderna has published its preliminary findings.

Moderna COVID/flu vaccine phase 3 results

The mRNA-1083 vaccine targets the strains of COVID that circulated in late 2023 plus the H1N1, H3N2, and B/Victoria flu strains.

The latest data was collected from two arms of a larger study that involved around 8,000 people – one tested the mRNA-1083 vaccine against GSK’s Fluarix in adults aged 50 to 64 and another against Sanofi’s Fluzone HD in people 65 and older. Fluzone is a high-dose vaccine for older people.

The phase 3 clinical trial is a randomized, observer-blind, active control study evaluating the safety, reactogenicity, and immunogenicity of mRNA-1083 in two independent age group cohorts of approximately 4,000 adults each. One cohort, adults 65 years and older, compared the mRNA-1083 vaccine to the co-administered Fluzone quadrivalent vaccine and Spikevax, Moderna’s currently licensed COVID-19 vaccine. The other cohort of adults 50 to 64 years of age compared mRNA-1083 to co-administered, Fluarix quadrivalent vaccine and Spikevax.

Here are the key preliminary results from the phase 3 study:

• In both age cohorts, mRNA-1083 elicited statistically significantly higher immune responses against three influenza virus strains (H1N1, H3N2, and B/Victoria) and SARS-CoV-2.
• In the 65 years and older cohort, overall Geometric Mean Ratios (GMRs) of the mRNA-1083 group compared to the Fluzone HD group for the influenza strains were 1.155 (oversimplifying, this shows that the combination vaccine is about 15.5% more effective) for A/H1N1, 1.063 (6.3% more effective) for A/H3N2 and 1.118 (11.8% more effective) for B/Victoria.
• The GMR of mRNA-1083 compared to Spikevax for the SARS-CoV-2 variant Omicron XBB.1.5 was 1.641 (64.1% more effective).
• In the 50 to 64 years of age cohort the GMRs of the mRNA-1083 group compared to the Fluarix group for the influenza virus strains were 1.414 (41.4% more effective) for A/H1N1, 1.380 (38.0% more effective) for A/H3N2, and 1.216 (21.6% more effective) for B/Victoria.
• The GMR of mRNA-1083 compared to Spikevax for the SARS-CoV-2 variant Omicron XBB.1.5 was 1.308 (30.8% more effective).

Summary

The combination flu/COVID vaccine to protect against both COVID-19 and influenza generated a much stronger immune response in adults aged 50 and over compared to separate flu shots against the viruses in a phase 3 clinical trial.

Moderna is targeting the new vaccine for the 2025 respiratory disease season, but that depends on regulatory approval and manufacturing scale-up. Since I get both vaccines separately, I would be thrilled to prevent both flu and COVID with one vaccine.

When there are more updates to this vaccine’s launch date and other clinical trial information, I’ll be sure to post it here.