Novavax, the Maryland-based biotechnology company, announced on June 12, 2025, promising results from its Phase 3 trial testing a novel combination vaccine targeting both COVID-19 and seasonal influenza. The study, which involved approximately 2,000 adults aged 65 and older, revealed that the immune responses elicited by the combination vaccine, named CIC, as well as its standalone trivalent influenza vaccine (tNIV), were comparable to those triggered by established vaccines Nuvaxovid and Fluzone HD.
This clinical trial was specifically designed to collect descriptive data on immune responses to three influenza strains—H1N1, H3N2, and B—as well as SARS-CoV-2, the virus responsible for COVID-19. Novavax’s combination vaccine aims to simplify immunization strategies by protecting vulnerable older adults against both illnesses in a single shot, a significant convenience and public health advancement.
According to the data released, both the CIC and standalone influenza vaccines induced robust immune responses, with a 2.4- to 5.7-fold increase from baseline antibody levels. Importantly, these responses were on par with those generated by the reference vaccines: Nuvaxovid, Novavax’s own COVID-19 vaccine, and Sanofi’s Fluzone HD, a high-dose influenza vaccine widely used in older populations.
Safety profiles were encouraging as well, with over 98% of adverse events reported as mild or moderate, underscoring the tolerability of these vaccine candidates in an older demographic often at higher risk for severe disease from both influenza and COVID-19.
Novavax’s announcement follows on the heels of positive signals from a previous Phase 2 trial, reinforcing confidence in the vaccine’s potential. The company emphasized that while the Phase 3 study was not designed to demonstrate statistical significance, the descriptive data are instrumental in shaping the design of a future registrational Phase 3 trial. This subsequent trial would aim to gather the definitive data required for regulatory approval and market authorization.
The combination vaccine represents a strategic innovation in infectious disease prevention, particularly for older adults who face compounded risks during flu season amid the ongoing COVID-19 pandemic. Simplifying vaccination schedules by combining protection against multiple respiratory viruses could improve vaccine uptake and compliance, a critical factor in public health outcomes.
Novavax’s CIC vaccine candidate and standalone flu shot were evaluated side-by-side against their respective benchmark vaccines. This head-to-head comparison helps establish the combination vaccine’s efficacy and safety relative to current gold standards. The company’s approach reflects a growing trend in vaccine development toward multivalent or combination formulations that address multiple pathogens simultaneously.
The study’s focus on adults aged 65 and older is particularly noteworthy. This age group is disproportionately affected by both COVID-19 and influenza, often experiencing more severe symptoms and higher rates of hospitalization and mortality. The prospect of a single vaccine providing dual protection could alleviate the logistical challenges of multiple immunizations and reduce the burden on healthcare systems.
Novavax’s CEO expressed optimism about the results, highlighting the robust immune responses and favorable safety profile as encouraging milestones. The company is now preparing for a larger Phase 3 trial that will seek to confirm these findings with statistical rigor and support regulatory submissions worldwide.
While the Phase 3 trial presented descriptive data rather than conclusive evidence, the findings mark a significant step forward in the quest for more comprehensive respiratory virus vaccines. The success of such combination vaccines could revolutionize seasonal vaccination strategies and offer enhanced protection during overlapping viral outbreaks.
Industry observers note that Novavax’s efforts align with a broader push by pharmaceutical companies to develop next-generation vaccines that address multiple threats simultaneously. The COVID-19 pandemic has underscored the need for adaptable and efficient vaccine platforms, and combination vaccines like Novavax’s CIC candidate may become an integral part of future public health responses.
As the company moves toward a registrational Phase 3 study, regulators and healthcare providers will be watching closely. The potential approval of a combination COVID-19 and influenza vaccine could streamline immunization campaigns, particularly in countries with aging populations and limited healthcare resources.
In addition to its public health implications, the development of such a vaccine could have significant commercial impact. Combining vaccines into a single dose reduces manufacturing and distribution complexities, potentially lowering costs and improving accessibility.
Novavax’s announcement comes at a time when vaccine innovation remains a priority globally. The company’s ability to demonstrate comparable immune responses to established vaccines in a vulnerable population is a promising sign of progress.
Looking ahead, the company’s planned registrational Phase 3 trial will be critical in validating the combination vaccine’s safety and efficacy on a larger scale. If successful, this could pave the way for regulatory approvals and widespread use, offering a new tool in the fight against respiratory illnesses.
Ultimately, Novavax’s work exemplifies the ongoing evolution of vaccine science, aiming to meet the challenges posed by multiple infectious diseases in a single, effective intervention.