Moderna on Thursday announced positive interim results from the Phase 1/2 trial of its investigational combination vaccine against influenza and Covid-19.

Flu and Covid-19 represent a significant seasonal burden for individuals, providers, healthcare systems and economies.

Combination shots aim to target both respiratory viruses that typically surge at the same time of the year.

The Phase 1/2 clinical trial evaluated the safety and immunogenicity of mRNA-1083 compared to a standard dose influenza vaccine Fluarix, in adults 50-64 years of age.

It was also compared against an enhanced influenza vaccine Fluzone HD in adults 65-79 years of age. For both age groups, mRNA-1083 was compared against the Spikevax booster.

Antibody titer levels for mRNA-1083 were similar to or greater than both of the flu vaccines.

Also, neutralising antibody titers were similar to the bivalent Spikevax booster.

Local and systemic effects for mRNA-1083 were similar to Moderna’s standalone Covid booster. No new safety concerns were noted compared to the Covid vaccine.

“With today’s positive results from our combination vaccine against flu and Covid-19, we continue to expand our Phase 3 pipeline,” said Stephane Bancel, Chief Executive Officer of Moderna, in a statement.

“Combination vaccines offer an important opportunity to improve consumer and provider experience, increase compliance with public health recommendations, and deliver value for healthcare systems,” Bancel added.

The company now plans to begin a Phase 3 trial of mRNA-1083 in 2023 and is targeting potential regulatory approval for the combination vaccine in 2025.

“We are excited to move combination respiratory vaccines into Phase 3 development and look forward to partnering with public health officials to address the significant seasonal threat posed to people by these viruses,” Bancel said.

Influenza epidemics occur seasonally and vary in severity each year. It affects people of all ages, but older adults are disproportionately affected by influenza and its complications.

Worldwide, influenza leads to 3-5 million cases of severe diseases and 290,000-650,000 influenza-related respiratory deaths annually, despite the availability of current influenza vaccines.