Influenza vaccine research has one ultimate goal: finding the effective vaccine which generated stable antibody recognizing the influenza virus. Influenza viruses have notoriously known for rapid genome mutation, thereby vaccine formulated this year will not work properly for preventing the coming-years flu, making the flu vaccine needs to be administered on the regular basis. This is exacerbated by the fact that influenza virus has eight segmented genome which can be shuffled among different strains, creating a new combination. Novel strain-viruses are crafted during that processes or termed as genetic shift and unfortunately, our immune cells don’t have collection of antibodies for tackling the virus. The viruses are able to spread pervasively and inevitably, viral epidemic followed, such as swine flu or H1N1 viral outbreak occurred several years ago.
Recent research explores the nature and presence of boardly-neutralizing antibody (bnAb) which targets a great number of influenza virus strain. As a sort of universal-influenza vaccine, this vaccine should aim on the parts of viruses which don’t change a lot along the years or in other words the sequence conservation is maintained. Current antibodies mostly use the protein derived from head part of haemaglutinin protein. Heamaglutinin is a protein located in the outside of viral capsid and needed to enter the host’s cell. As the protein is exposed into the environment, targeting this protein should resulted in an effective vaccine. However, the downside is that like another outer membrane protein, heamaglutinin is actually under strong selective pressure, so genetic mutation occurs rapidly.
New finding offers an alternative for designing the flu vaccine. Instead of targeting the head parts of heamaglutinin, the neck part beneath of the head used for this purpose. Genomic comparison shown that this region underwent relative little genetic mutation, thus making a perfect choice for vaccine candidate. Although similar in different influenza viruses’ strain, creating vaccine from this region isn’t easy as it predicted. Removing the head parts (which has large variability) tends to make the protein unstable and owing to its small size it is apparently that the particle don’t elicit strong immune protection. Research comes up for overcoming this downside by attaching the stem parts into ferritin nanoparticles. Single molecule of nanoparticles holds several vaccine-proteins and yet the protein still retain its functional capabilities, resulted in an effective protection towards different strain of influenza viruses.
In spite of its infancy, I personally believe that the research for finding the universal antibody for influenza should be taken an attention as it has promising future in solving the global health problems caused by emerging infectious-viruses.
This writing is based on this following article: http://news.sciencemag.org/biology/2015/08/universal-flu-vaccine-horizon.