While traditional vaccines can offer annual protection from the latest flu strains, the viruses mutate and evolve so fast that we're right back where we started the following year. That's where a revolutionary new vaccine could change everything.
Vaccines currently work by essentially teaching our immune systems to recognize a pair of key proteins, known as HA and NA, found on viruses. But those proteins constantly change, which is why we always need new vaccines. The key is to find a way to target something on the viruses that never changes, hence conferring lasting immunity against multiple flu virus strains. One previous proposal for a universal flu vaccine involves going after other proteins on the flu virus that don't evolve as quickly as the NA and HA proteins.
But a new kind of vaccine takes it one step further, targeting the underlying RNA-driven processes that create the NA and HA proteins, regardless of their precise form. New Scientist has the story:
The mRNA that controls the production of HA and NA in a flu virus can be mass-produced in a few weeks, says Lothar Stitz of the Friedrich-Loeffler Institute in Riems Island, Germany. This mRNA can be turned into a freeze-dried powder that does not need refrigeration, unlike most vaccines, which have to be kept cool. An injection of mRNA is picked up by immune cells, which translate it into protein. These proteins are then recognised by the body as foreign, generating an immune response. The immune system will then recognise the proteins if it encounters the virus subsequently, allowing it to fight off that strain of flu.
RNA vaccines are especially attractive because, unlike proposed DNA vaccines, there's no chance of them getting spliced into the human genome and disrupting normal genetic behavior. And now German researchers have discovered a protein called protamine, which protects the RNA vaccines from being ripped apart in the bloodstream. We still need to make sure these vaccines actually work on humans the way we think they should, but the early results have been very promising indeed. Check out the complete article over at New Scientist for more.