Murdoch Children’s Research Institute Launches Sniffles Trial Testing Needle-Free Flu Vaccine in Australian Kids

Launch of the Sniffles Trial: A Step Forward in Pediatric Vaccine Research

The Murdoch Children’s Research Institute has kicked off the Sniffles trial, a groundbreaking study examining how a needle-free nasal spray flu vaccine performs in Australian children compared to the traditional injection. This initiative targets kids aged two to nine years in Victoria, aiming to uncover key insights into immune responses that could reshape flu prevention strategies for young ones across the southern hemisphere. With FluMist, the nasal spray option manufactured by AstraZeneca, now available in Australia for the first time in 2026, researchers see a timely chance to address longstanding barriers like needle phobia while enhancing protection against seasonal influenza.

FluMist introduces a live attenuated influenza vaccine delivered directly into the nostrils, mimicking natural infection pathways to stimulate both local mucosal immunity in the respiratory tract and systemic responses throughout the body. The trial's design allows parents to choose their preferred method, making participation more accessible and reflective of real-world preferences. Early recruitment is underway, with 270 children set to contribute nasal swabs, blood samples, and questionnaires over several visits starting from April 2026.

The Growing Need for Better Flu Protection in Australian Kids

Influenza hits Australian children hard each year, with 2024 marking a record high of over 365,000 confirmed cases nationwide, the majority affecting those under 10 years old. Hospitalizations, emergency visits, and school absences spike during peak seasons, straining families and healthcare systems alike. Despite free vaccines for kids under five in most states, uptake lags: in Victoria, only 32 percent of children aged six months to five years and 15 percent of those five to 15 received their shot in 2024.

This gap stems partly from logistical hurdles and fear of needles, which deters many parents. A 2025 national survey found 72 percent would prioritize flu vaccination if a needle-free alternative existed, highlighting the potential game-changer of options like FluMist. By studying these responses, the Sniffles trial not only seeks to boost immediate protection but also inform long-term strategies to curb flu's toll on child health.

FluMist Explained: How the Nasal Spray Vaccine Works

FluMist stands out as a quadrivalent live attenuated influenza vaccine, containing weakened strains of the four main flu viruses circulating that season. Unlike inactivated injections that primarily trigger antibody production in the blood, the nasal spray introduces live but attenuated viruses into the upper respiratory tract. This process closely resembles natural exposure, prompting the body to produce protective immunoglobulins A at mucosal surfaces—the first line of defense against airborne pathogens.

Administered as a quick spritz into each nostril, FluMist requires no needles, syringes, or refrigeration post-thawing, simplifying delivery in clinics, schools, or pharmacies. Approved by Australia's Therapeutic Goods Administration for children two to 17 years, it matches the safety profile seen in the UK and US, where millions of doses have been given annually. Step-by-step, the vaccine replicates infection without causing illness: viruses attach to nasal cells, alerting immune cells like T-cells and B-cells; these multiply and patrol airways, neutralizing future invaders before they spread deeper.

Comparing Immune Responses: Injection vs. Nasal Spray

The core of the Sniffles trial lies in dissecting these differences. Injectable vaccines excel at humoral immunity—blood-based antibodies that circulate systemically—but may fall short on mucosal barriers where flu enters. Nasal sprays, conversely, prime IgA antibodies right at entry points, potentially offering broader, longer-lasting defense against variants.

Participants undergo baseline sampling, vaccination (parent-chosen), a week-later check-in, optional second dose for at-risk kids after 30 days, and a final assessment 30 days post-last dose. Researchers analyze nasal lining cells for local responses and blood for antibodies and T-cells, comparing metrics like neutralization potency and cross-reactivity. This head-to-head approach builds on global data showing nasal vaccines sometimes outperform injections in kids during mismatch seasons, though efficacy hovers 50-70 percent for both, varying by strain dominance.

For deeper reading on vaccine mechanisms, explore the TGA's 2026 seasonal influenza vaccines report.

Photo by Thorium on Unsplash

Behind the Trial: Expertise at Murdoch Children’s Research Institute

Leading the charge is Associate Professor Shidan Tosif, a consultant pediatrician at the Royal Children’s Hospital and MCRI clinician-scientist fellow. Her team, including coordinators Abigail Fernando and Annette Alafaci, draws from SAEFVIC—the Surveillance of Adverse Events Following Vaccination in the Community program—to ensure rigorous monitoring. Samples head to the UK's MOVE Consortium and Doherty Institute's WHO Collaborating Centre for analysis, bridging local data to global standards.

MCRI's Vaccine Group, focused on new vaccines and uptake, positions this trial within broader efforts like the Vaccine Champions Program, which tackles hesitancy through education. Tosif emphasizes: “The nasal spray has been safely used for years overseas; now we can study how Australian kids respond, filling critical data gaps.” This work underscores MCRI's role in translating lab insights to policy.

University of Melbourne's Role in Cutting-Edge Pediatric Research

Murdoch Children’s Research Institute operates in tandem with the University of Melbourne's Melbourne Medical School and the Royal Children’s Hospital, forming a powerhouse trio for child health innovation. University researchers contribute to trial design, immunology assays, and data interpretation, leveraging facilities like the Doherty Institute for virology expertise.

This collaboration exemplifies Australian higher education's strength in translational research: from bench to bedside, addressing national priorities like immunization equity. MCRI scientists hold joint appointments, fostering PhD training and postdoc opportunities in vaccinology—a field booming amid post-COVID vaccine tech advances. Such partnerships not only drive discoveries but also train the next generation of researchers tackling respiratory threats.

Explore careers in this space via research jobs in Australia.

Filling Global Gaps: Southern Hemisphere Data for WHO

Unlike northern hemisphere trials dominating WHO strain selection, southern data—especially from kids—is sparse. Sniffles addresses this by supplying anonymized blood sera, helping calibrate vaccines against regional drifts. Flu strains evolve rapidly; mismatches reduce efficacy by 20-50 percent, hitting unvaccinated kids hardest.

This WHO tie-in elevates the trial's impact, potentially influencing formulations for billions. Past collaborations, like cell-based vaccines showing 60 percent protection in Aussie kids, pave the way. By prioritizing pediatric responses, the study champions equity in global health preparedness.

Learn more from the WHO's influenza vaccine recommendations.

Overcoming Vaccine Hesitancy and Boosting Uptake

Needle aversion affects up to 20 percent of kids, leading to tears, delays, and skipped doses. FluMist sidesteps this, with surveys showing parental enthusiasm. Yet challenges persist: live virus concerns (despite attenuation), mild side effects like runny nose (5-10 percent), and contraindications for immunocompromised.

Trial questionnaires capture real-time experiences, informing rollout strategies. Benefits include school-based programs, reducing GP overload. Higher ed plays key: uni-led education campaigns could lift rates 20-30 percent, mirroring UK successes where nasal sprays halved hesitancy.

Photo by John Jennings on Unsplash

• Pros: Painless, mimics natural immunity, high acceptability.
• Cons: Not for egg-allergic/asthmatic kids, needs fridge storage.
• Comparisons: Injection safer for high-risk, nasal better for healthy.

Safety, Efficacy, and Lessons from International Trials

FluMist's track record: US CDC recommends for 2-49yo healthy; efficacy 40-60 percent vs. injection's 50-70 percent, but superior in some mismatched years. Aussie PAEDS-FluCAN data shows vaccines cut hospitalizations 65 percent in kids.

SNIFFLES builds on this, testing southern strains. Risks minimal: wheezing rare (1/1000), no Guillain-Barré link. Long-term, mucosal training may curb transmission 30 percent better.

Future Horizons: Implications for Australian Child Health Research

If successful, Sniffles could spur wider FluMist adoption, hybrid schedules, or next-gen sprays for RSV/COVID. Higher ed benefits: more grants, trials, jobs in immunology. MCRI/Unimelb model inspires national networks, tackling multimorbidities like asthma-flu overlaps.

Stakeholders—from parents to policymakers—gain actionable insights. As flu evolves, proactive research ensures Australia's kids stay ahead, healthier, and school-ready. Parents interested: check eligibility at MCRI's site.

For related opportunities, see research positions in higher education.