By Gary Nabel, MD, PhD, Chief Scientific Officer, Sanofi and John Shiver, PhD, Senior Vice President, Global R&D, Sanofi Pasteur

In 1918, as society was coping with the aftermath of World War I, an even deadlier foe spread rampant around the globe: the Spanish flu. Its effects were devastating, fusing classic flu symptoms with pneumonia so severe that patients turned blue from the lack of oxygen. When it was all said and done, an estimated 50 million people had died, serving as a warning to the world on the impact of influenza. 

The influenza virus (pictured) has challenged researchers for decades.

Scientists wasted little time searching for the cause, and by the 1940s, they had developed the first prototypes for modern seasonal influenza vaccines. But one problem remained – the virus demonstrated its ability to mutate. This phenomenon, known as antigenic drift, has created a major roadblock in efforts to combat influenza. 

Thankfully, in partnership with global health authorities, scientists have developed yearly vaccines that help protect against the primary strains of the virus each season. However, they do not protect against every strain, meaning yearly vaccination is required. For this reason, the ultimate goal is a universal vaccine that can durably protect against families of the influenza virus for longer than one year, but this task has proven elusive and remains a major unmet need for global health.

This challenge brings us to the American Association for the Advancement of Science (AAAS) annual meeting1,  where we will convene leading scientists and public health experts to discuss the latest advancements in the quest for a universal flu vaccine. These new approaches affirm our commitment to safeguarding the public further by increasing vaccine coverage against diverse strains of influenza. 

One approach we’re exploring at Sanofi to improve immunity is to target the hemagglutinin (a viral protein found on the surface of influenza cells) to more effectively increase a vaccine’s breadth of protection. 

In the clinic, advanced models and translational trials are also being used to identify biomarkers that facilitate development of an improved flu vaccine. 

The hemagglutinin (pictured) is one of many influenza proteins scientists are exploring in universal flu vaccine research.

We’re excited to see how our research progresses over the next few years, but it’s important to keep in mind a true universal influenza vaccine will likely take years to achieve. That said, it may be possible to substantially improve the efficacy and breadth of seasonal vaccines sooner, and more broadly protective influenza vaccines could emerge that may better protect public health. Investments in new technologies, like recombinant vaccines, are one way we’re working to reach these milestones.  

Influenza continues to cause tens of thousands of deaths each year and even more frequent hospitalizations. The threat of another global pandemic remains a grave concern, and efforts to improve influenza immunity remain critical. 

That is why it’s essential we fulfill our public health commitment through existing influenza vaccinations – which have helped prevent serious illness, hospitalization and spread of disease – while we pursue the next generation of flu vaccines. While a truly universal vaccine may be a distant goal, we’re optimistic that influenza countermeasures can be improved substantially in coming years.


  1. On February 16, 2019, Sanofi will partner with the AAAS to host a scientific symposium featuring leading public health experts on the quest for a universal flu vaccine.