Could One Shot Replace Flu and COVID-19 Vaccines?

TOPLINE:

A novel multicomponent messenger RNA (mRNA) vaccine, mRNA-1083, demonstrated noninferiority to standard influenza and COVID-19 vaccines in adults aged 50 years or older, eliciting higher immune responses against most influenza strains (A/H1N1, A/H3N2, B/Victoria, and B/Yamagata) and SARS-CoV-2 (Omicron XBB.1.5), according to a pivotal phase 3 study.

METHODOLOGY:

• The mRNA-1083 is an investigational, multicomponent vaccine that combines the components of a hemagglutinin-based influenza vaccine (mRNA-1010) and a second-generation SARS-CoV-2 vaccine encoding the spike glycoprotein’s N-terminal and receptor-binding domains.
• Researchers present interim findings of a phase 3 trial that assessed the immunogenicity and safety of this vaccine in adults aged 50 years or older across the United States, enrolling participants between October 19, 2023, and November 21, 2023.
• They randomly assigned 8061 participants to receive either the mRNA-1083 vaccine plus placebo or the active comparator vaccines for seasonal influenza or COVID-19.
• Participants were stratified into those older than 65 years (n = 4017; 54.2% women) and those aged 50-64 years (n = 3998; 58.8% women).
• The primary objective was to demonstrate the noninferiority of humoral immune responses — measured by antibody levels — to mRNA-1083 vs active influenza and COVID-19 vaccines against vaccine-matched strains, 29 days post-vaccination.

TAKEAWAY:

• The mRNA-1083 vaccine demonstrated noninferiority to the active comparator vaccines against the four influenza strains and SARS-CoV-2 in both age groups, as determined by a 97.5% CI lower bound greater than 0.667 for the geometric mean ratio and more than −10% for the seroconversion rate difference.
• In adults aged 50-64 years, mRNA-1083 elicited superior immune responses to all four influenza strains relative to the active comparator influenza vaccines, whereas in adults aged 65 years or older, superiority was observed for three strains (A/H1N1, A/H3N2, and B/Victoria).
• Most local and systemic adverse reactions were grade 1 or 2 across vaccine groups. Grade 4 adverse reactions, all of which were systemic events (fever), were reported by two participants in each age group.
• In both age groups, no severe or serious adverse events or adverse events of special interest were deemed vaccination-related. No deaths or cases of myocarditis or pericarditis were reported.

IN PRACTICE:

“As such, an annual vaccination campaign with a multicomponent vaccine could occur during the seasonal period when the burden of respiratory hospitalizations is the greatest, while allowing for a standalone COVID-19 vaccine option for additional doses or if the vaccine is updated in the interim should any antigenically divergent strain emerge,” the authors wrote.

SOURCE:

This study was led by Amanda K. Rudman Spergel, MD, Moderna Inc., Cambridge, Massachusetts. It was published online on May 7, 2025, in JAMA.

LIMITATIONS:

The efficacy of mRNA-1083 was not established in the study and requires further investigation. Although the diversity of the study population mirrored that of the general US population, the results may not be generalizable to other geographic areas.

DISCLOSURES:

This study was funded by Moderna, Inc. Many authors were employees of Moderna and may hold stock or stock options.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.