Canada has become the first country to authorise an mRNA vaccine against seasonal influenza for adults aged 50 and over, approving Moderna’s mFLUSIVA for the 2026-27 respiratory season.
The regulator also authorised mCOFLU, a combined mRNA vaccine against influenza and COVID-19, for the same age group. The decision was announced on 5 November after markets closed.
What has been approved
Health Canada’s authorisation covers adults aged 50 and above, a group that carries a disproportionate share of influenza hospitalisations and deaths. The approval follows the US Food and Drug Administration’s decision in August to authorise mFLUSIVA for the same age group.
Seasonal flu vaccines have been made using chicken eggs or cultured cells for decades. The mRNA platform instead delivers genetic instructions that prompt the body to produce a viral protein, which the immune system then learns to recognise.
The advantage claimed for the technology is speed. A conventional vaccine requires a strain to be grown and characterised months in advance, which is why the annual flu vaccine is sometimes a poor match for the virus that circulates. An mRNA vaccine can be updated to a new strain sequence in weeks rather than months.
The regulatory bar
Approval for a new flu vaccine platform requires evidence of immunogenicity, the ability to provoke an immune response, and of safety in a large population. It also requires evidence that the vaccine protects against strains that are circulating, which is harder to demonstrate when the virus changes each year.
Regulators in several countries have been cautious about mRNA flu vaccines because the correlates of protection for influenza are less well established than for COVID-19. An authorisation for adults over 50 is a narrower approval than a universal one, and it will be followed by monitoring of real-world effectiveness during the season.
The combined influenza and COVID-19 vaccine is the more commercially significant product, since it would reduce the number of injections in an annual campaign. Combination vaccines have historically been difficult to develop because the immune response to one component can interfere with the other.
What it means for patients
For most people over 50, the existing egg-based and cell-based vaccines remain effective and widely available. The mRNA products offer an alternative, not a replacement, and their uptake will depend on how they are priced and whether health systems recommend them.
The timing of the authorisation means the vaccines are unlikely to be widely used in the current season, since procurement and distribution for the northern hemisphere campaign are largely settled by early autumn. The more realistic impact is in 2027-28 and beyond.
Moderna has been under financial pressure as demand for its COVID-19 vaccine has fallen, and it has been cutting costs while trying to establish its respiratory vaccine portfolio. A first-in-world approval for an mRNA flu vaccine gives it a regulatory precedent it can use in other markets.
The wider significance
Influenza kills hundreds of thousands of people worldwide each year, and vaccine effectiveness varies widely depending on how well the chosen strains match those that circulate. A platform that can be updated quickly and manufactured at scale would reduce that variability.
The approval also marks a shift in how regulators treat mRNA technology. What began as an emergency authorisation during a pandemic is now being assessed through the ordinary licensing pathway for a routine seasonal vaccine, which is a test of whether the platform can compete on cost and convenience with established manufacturers.
