Finding a more effective flu vaccine

Drs. Norbert Herzog & David Niesel

Drs. Norbert Herzog & David Niesel

Medical Discovery News

While most think of the flu as a miserable weeklong inconvenience, it can be quite serious. In fact, it kills an average of 36,000 Americans every year.

The virus can mutate quickly, so to create an effective vaccine, each year scientists must predict the dominant strains. But advances in nanoparticles and molecular biology have the potential to revolutionize the flu vaccine.

Current flu vaccines include three different strains. To harvest these strains, chicken eggs are infected with the different types of influenza viruses included in the yearly vaccine. That’s a lot of eggs, considering millions of doses are needed! It just goes to show, to make omelets you have to break some eggs.

But all those laying hens may be out of a job thanks to recent advances in protein nanoparticle technology.

Ferritin is a common protein used to store iron, but it has an extraordinary ability. Like the Mighty Morphin Power Rangers who can combine all of their vehicles into one giant robot, 24 of these proteins can self-assemble into a sphere with a hollow core and eight spikes pointing out from the center.

Then, scientists can use molecular biological technology to insert a foreign protein, which becomes part of the spikes sticking out from the ferritin-made sphere. To the human immune system, this is basically like waving a red flag — it immediately detects and targets the foreign intruder. By attaching a major antigen from the flu virus (in this case, hemagglutinin protein) to the “mighty” ferritin sphere and then injecting it, the body will start a campaign against the invading protein. The antibodies produced in this campaign will protect against a flu infection.

Creating flu vaccines this way would be faster and more effective. When tested on animals, the nanoparticle flu vaccine produced 30 times more anti-flu antibodies in mice and 10 times more in ferrets than the current vaccine. This new nanoparticle vaccine has incredible potential for humans.

And it gets better. The protein used was from a virus isolated during the 1999 flu outbreak, but it also ended up protecting subjects from another related strain that hit in 2007. This is unusual, because the virus changes over time. But it’s probably because the antibodies produced in response to the nanoparticle vaccine protect against shared portions of the flu protein. So the good news is that if one vaccine can prevent multiple types of the flu, a universal flu vaccine may be possible using this same technology.

Nanoparticle technology could be used to develop vaccines for other viruses, bacteria and parasites. If it’s as effective in humans as it is in animals and the costs of producing it are controlled, nanoparticle vaccines could become the standard for cheap, safe and effective vaccines in the future.


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