Tiny but mighty particle fights against the flu

The specificity of our immune system is often a blessing; it using identifies minuscule, particular features of a pathogen to differentiate it from a host of possible disease causing specimens, and then tailor its response accordingly. However, certain viruses, including influenza, are able to turn this system on its head and engineer evolutionary changes to the specific regions of the virus that the immune system targets. This often explains why a flu vaccine will leave us immune to some but not all strains of the virus.
As a result, scientists are exploring the efficacy of perhaps not being so specific, but instead focusing on general features shared by influenza viruses, such as hemagglutinin, the H protein of the HA complex. HA is the surface protein responsible for allowing viruses to inject their genetic material into vulnerable host cells. This process can be blocked by broadly neutralizing antibodies, which defend against one of two types of HA classes. While these antibodies alone could serve as a therapy against flu infection, antibodies as a whole are often difficult to administer. They must be refrigerated before use, injected because they cannot endure the digestive tract and still run the risk of being rejected by the immune system.
To counter this problem but still use the generality exemplified by broadly neutralizing antibodies, researchers at Johnson and Johnson searched for a small molecule that could essentially out bind the antibody that would typically attach to the HA. After multiple rounds of screening and making adjustment to the molecules, scientists tested a modified molecule in mice models injected with the flu and the results were promising-the mice survived despite receiving doses of the flu that should have been lethal. The same molecule was trailed in human bronchial cells. However, far more research and consideration is needed before this small molecule therapy can materialize as a treatment and/or prevention of flu infection in humans.

-Riasoya Jodah
Source: Timmer J. A small-molecule drug can block a broad range of flu viruses in mice. Ars Technica. https://arstechnica.com/science/2019/03/a-small-molecule-drug-can-block-a-broad-range-of-flu-viruses-in-mice/. Published March 11, 2019. Accessed March 18, 2019.