Most flu vaccines aim at a single target on the influenza virus. GSK is wagering that hitting two will protect people better — and its mRNA flu vaccine is advancing on that bet.
Standard flu shots target hemagglutinin (HA), one of the virus’s two key surface proteins. GSK’s vaccine adds a second target, neuraminidase (NA). The company argues that going after both could improve protection, reduce illness severity, and limit transmission.
The data so far
In a Phase 2 trial of 971 adults, two vaccine candidates both generated robust immune responses to HA and NA from influenza A and B strains, in younger and older adults, with an acceptable safety profile. GSK picked its optimized candidate for Phase 3 testing, expected to begin later in September 2026.
Why it matters
mRNA flu vaccines are heating up: Moderna’s mFLUSIVA became the first FDA-approved mRNA flu shot in August 2026 — but, like traditional vaccines, it targets only HA. GSK’s two-antigen approach is a potential differentiator. “These promising data support the potential to better protect people from flu with a vaccine designed to target both HA and NA,” said GSK vaccines R&D head Sanjay Gurunathan. (GSK acquired the candidates from CureVac in 2024.) It’s still Phase 2 data — the Phase 3 will be the real test.