Developing a universal flu vaccine by targeting the supporting proteins

Coughing, sneezing, high fever, and body aches, these are all symptoms of the flu. Each winter season people are stricken down by this illness. Often mistaken for a stomach bug, the flu attacks the lungs of people resulting in strong coughs, sore throat and sometimes pneumonia. Annually there are over 250,000 deaths from influenza usually in the elderly or the young. Depending on the type of virus circulating that year, the influenza season can be mild or could be severe. The influenza virus has a coat of protein spikes and caps on its surface (see below) that help protect it from damage and allow it to sneak past your immune system.

3 Dimensional model of influenza virus 3d graphical representati

Influenza virus with spikes and caps coating its surface

The virus can change the configuration and shape of this surface covering to further help evade the immune system. For this reason, each influenza season is different from the next and there could even be more than one virus circulating around. To combat this, scientists collect data and theorize about which virus strains will be present that season so they can make vaccines towards it. Sometimes they incorrectly identify which viruses will be present and even when they get them right the process is expensive and time consuming. The cost of developing a flu vaccine cocktail can be upwards of tens of millions of dollars each year. To combat this scientists have been chasing the holy grail of vaccine research, a flu vaccine that targets all influenza viruses regardless of how they change their surface.

Two research groups, one out of Maryland and one out of the Netherlands, have recently published work detailing the development of just such a universal vaccines. The protein they are targeting was identified in 2009. It is the stalk protein that holds the cap proteins up. It acts like the stalk on a mushroom. This protein was found to be constant among a variety of influenza viruses but initial attempts to target it for vaccination were ineffective. In order to make it more effective, the two research groups used different approached to modify the stalk protein to make them more stable and reactive to the immune system. When they did this, both groups found the vaccine could protect mice from a lethal dose of H1N1 (swine flu) and various bird flus. Underwhelmingly however, the vaccine was unable to stop infection in monkeys (a more appropriate model for human use). It was only able to reduce the severity of the infection. Additionally, in ferrets, which are the best model for human infection, the vaccines could only prevent infection in a handful of the animals.

There is still much work to be done before the Holy Grail dream of a flu vaccine is realized. This work will take a lot of collaboration and bright minds to solve the problem. If we could find a flu vaccine that could protect against all varieties of the bug then we would be on our way to potentially eradicating the disease from our culture.

Header photo credit: “H1N1 navbox” by Cybercobra 

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