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For many people, influenza is only top of mind during peak flu season — typically December to February in the U.S.1 However, the threats associated with this potentially severe and deadly infectious disease are what drive influenza vaccine suppliers to work around the clock all year round to develop and distribute seasonal influenza vaccines to help protect our communities. Unlike most other infectious diseases, influenza represents a moving target — the circulating strains of the influenza virus change from year to year, making the development of vaccines especially challenging.2 However, one thing remains constant: the Centers for Disease Control and Prevention recommends annual influenza vaccination for children 6 months of age and older and adults as the best way to protect against influenza and influenza-related complications.3

On the front line of protection against influenza is Seqirus, one of the largest influenza vaccine providers in the world. The company is paving the way by advancing the next generation of messenger RNA (mRNA) vaccine technology: self-amplifying mRNA (sa-mRNA).

sa-mRNA: The next generation of mRNA vaccine technology

Traditional vaccines work by stimulating the immune system to produce antibodies in response to the presence of a pathogen.4 In contrast, mRNA vaccines give the immune system instructions to make a protein from a particular virus, such as an influenza virus.4 They stimulate the immune response and leave a blueprint to recognize and fight a future infection.4

As the next generation of mRNA vaccine technology, sa-mRNA provides instructions to not only make a protein but also amplify the amount of protein made.5 This means sa-mRNA can trigger production of more protein and more potent cellular immune responses than an equivalent amount of mRNA, subsequently increasing the body’s ability to fight the influenza virus.6 Producing influenza vaccines via sa-mRNA also may enable manufacturers to develop vaccines within a shorter timeframe because of the versatility of the technology.7

While the Covid-19 pandemic propelled advances in mRNA technology and research, resulting in mRNA becoming a common household term, Seqirus has been researching sa-mRNA technology as a viable influenza vaccine technology for a number of years.

“Although there is still work to do to assess the application of sa-mRNA technology in influenza, early research has displayed the platform’s potential as the next generation of influenza vaccine technology,” said Roberta Duncan, Vice President, mRNA Program Lead, at Seqirus. “We expect to advance our sa-mRNA technology from the preclinical phase into Phase 1 clinical trials later this year. We’re excited about the potential of sa-mRNA and will continue to follow the science and data as we pursue further development.”

Despite the promise of sa-mRNA technology, Seqirus continues to explore additional influenza vaccine technology advancements, including its adjuvanted, cell-based influenza vaccine combined with cell-based influenza technology. Both technologies are important elements of the company’s research and development pipeline and future influenza vaccine portfolio, which currently includes differentiated influenza vaccines for both seasonal and pandemic influenza.

Join the fight against influenza

As a leader in influenza prevention and pandemic preparedness, Seqirus continues to remain focused on annual influenza vaccination and preparation to support an influenza pandemic response. While many unknowns remain around the Covid-19 pandemic as SARS-CoV-2 continues to circulate worldwide and mutate, Seqirus recognizes that it remains mission critical to support public health by providing influenza vaccines that are safe and effective to protect our communities and decrease the burden of influenza illness on the healthcare system, especially to preserve capacity for Covid-19 patients.

Circulating influenza viruses will continue to constantly change, but thanks to vaccines, we can continue to help prevent this severe infectious disease. Join us in our fight by protecting yourself, your loved ones and your community by getting an annual influenza vaccine.

To learn more about Seqirus’ mission to fight against seasonal and pandemic influenza, visit the Seqirus website.


1Centers for Disease Control and Prevention (CDC). (2021). Flu Season. Retrieved from: Accessed January 2022.
2Sullivan, S.G.; Price, O.H.; Regan, A.K. Burden, effectiveness and safety of influenza vaccines in elderly, paediatric and pregnant populations. Ther. Adv. Vaccines Immunother. 2019;7:2515135519826481.
3CDC. (2021). Vaccine Effectiveness: How Well Do Flu Vaccines Work? Retrieved from: Accessed January 2022.
4CDC. (2022). Understanding mRNA COVID-19 Vaccines. Retrieved from: Accessed January 2022.
5Vigel, B., Lambert, L., Kinnear, E., et al. (2018). Self-Amplifying RNA Vaccines Give Equivalent Protection against Influenza to mRNA Vaccines but at Much Lower Doses. American Society of Gene & Cell Therapy. 10.1016/j.ymthe.2017.11.017
6Blakney, A. (2021). The next generation of RNA vaccines: self-amplifying RNA. Biochem (Lond). DOI: 10.1042/bio_2021_142.
7Ballesteros-Briones, M.C., Silva-Pilipich, N., Herrador-Canete, G., Vanrell, L., Smerdou, C. (2020). A new generation of vaccines based on alphavirus self-amplifying RNA. Curr Opin Virol. DOI: 10.1016/j.coviro.2020.08.003.