Researchers from Georgia State University have announced promising results that may place us one step closer to a universal flu vaccine. In a paper published today by Nature Communications, the group led by scientist Bao-Zhon Wang reports the generation of double-layered protein nanoparticles that induced long-lasting immunity to influenza A viruses in mice.
Researchers from Georgia State University targeted the inner part of the virus’ surface protein hemagglutinin (HA). While common vaccines target the outer part of HA, this segment is different for each virus, making each vaccine useful only for one specific strain. Researchers targeted the inner part of the protein, called stalk, by generating protein nanoparticles for effective drug delivery. Vaccination with the nanoparticles proved to be effective against several different influenza A viruses in mice.
Seasonal flu, also known as influenza A, is a highly contagious disease that spreads easily by air. While many think of the flu as just a seasonal inconvenience, this disease kills between 290,000 and 650,000 people every year, according to the WHO.
As influenza infects between 3-5 million people annually, great efforts have been made to control the disease. One of the most effective methods is through vaccination. While influenza vaccines have been used for over 60 years, there are many different types of influenza viruses and the virus often mutates. Furthermore, the immune response from vaccination wanes over time. For that reason, epidemiologists select three viral strains every year that they predict will be the most common and generate a different vaccine for them. This means that yearly immunized is necessary as the vaccine changes and one runs the risk that manufacturers identify the wrong strain, leading to an ineffective vaccine.
For that reason, great efforts have made to develop a universal vaccine, which will protect against all strains and require only one dose in a lifetime, a task that has proven challenging as the virus mutates quickly. While the results of this study are promising, further testing is necessary to assess the viability and efficacy of these nanoparticles in humans but this is an interesting step forward both in the understanding of the disease and for the generation of a universal vaccine.