A combined Covid-19 and flu vaccine could be on the horizon, though it will not be available for this year’s flu season.
On Monday, Moderna announced positive results from late-stage trials of its Covid-flu combination vaccine, known as mRNA-1083.
Moderna’s Chief Medical Affairs Officer, Francesca Ceddia, described the trial outcomes as “breakthrough results” and told CNN that participants receiving mRNA-1083 showed a better immune response compared to those who received separate flu and Covid vaccines.
This improvement was observed even among participants aged 65 and older, who typically respond less robustly to vaccines.
Ceddia emphasized the significance of the findings, stating, “When we think about the combination vaccine, we often only think about the element of convenience, one shot instead of two, but what is really, really breakthrough is the fact that you not only offer that advantage, you also offer the proof of clinical benefit. I think this is the most important message.”
While other companies have been working on combined Covid-flu vaccines, Moderna is the first to report positive results from late-stage trials.
Public health officials highlight the need for additional ways to protect against both viruses, given the high number of annual infections.
The US Centers for Disease Control and Prevention (CDC) estimated that between 35 to 64 million people in the United States contracted the flu last season. Of those, between 390,000 and 810,000 were hospitalized, and up to 71,000 died.
Last fall and winter, Covid-19 led to over half a million hospitalizations and 40,000 deaths, according to data presented to the US Food and Drug Administration’s independent vaccine advisers, who discussed updates for fall Covid vaccines.
Moderna’s Phase 3 trial was a randomized, observer-blind, active control study, ensuring that even the clinicians administering the vaccines did not know which vaccine the participants received. The trial included about 4,000 adults in each age group.
One segment of the study compared the immune response of adults aged 65 and older who received the mRNA-1083 vaccine with those who received a combination of Moderna’s Spikevax Covid-19 vaccine and an enhanced flu vaccine, Fluzone HD.
This comparison was made because seniors are recommended to receive more potent flu vaccines due to their weakened immune systems.
Another segment of the trial examined slightly younger adults, ages 50 to 64, comparing their response to the mRNA-1083 vaccine with those who received Spikevax and a standard dose flu vaccine, Fluarix.
Results indicated that the experimental combination vaccine elicited a statistically significant higher immune response against three strains of the flu and Covid-19 in both age groups compared to the co-administered vaccines.
“The titers are significantly higher,” Ceddia noted. “This is better actually.” A titer is a laboratory test that measures the number of antibodies in the blood, indicating immunity levels.
Regarding safety, Moderna reported that the combination vaccine was generally well-tolerated, with adverse reactions similar to those experienced with the separate vaccines.
The most common side effects included pain at the injection site, tiredness, muscle pain, and headaches.
The study has not yet undergone peer review, but Moderna plans to present the data at an upcoming medical conference and will submit it for publication. The company also intends to discuss potential next steps with the FDA.
Moderna CEO Stéphane Bancel told CNN, “We need to engage with regulators but our aspiration is to have it approved for fall 2025.”
Sue Peschin, president and CEO of the Alliance for Aging Research, emphasized the potential public health benefits of a combined vaccine.
She noted that vaccine hesitancy and fatigue have led to decreased uptake of standard and seasonal vaccines.
Studies show that only about 25% of eligible individuals received the latest Covid-19 vaccine, while nearly half of the adult population received the flu shot last season.
Peschin said, “We want to see that go up and if there’s a way to do that by combining the vaccines, then that’s better for everyone because it helps protect everyone in the community.
We would love to see the combination vaccines come to market if the FDA deems them safe and effective.”
