No one wants the flu, not even to get out of work unless you really hate your job that much, but that’s beyond the scope of anyone here at sci.casual. So, quite a few Americans get their annual flu shot (despite concerns that rates are going down a little). Interestingly, not a lot of countries feel that getting flu shots are that important, likely because the shots aren’t really effective – according to the linked article earlier in this sentence, it was 62% in 2013. It hasn’t changed much since then, but that isn’t going to stop immunologists and biochemists from making some headway against the flu.
There are three flavors (sorry, bad term) of influenzavirus: A, B, and C (there’s ‘D’ being proposed, primarily bovine). The virus that researchers want to pick apart is the Influenza A virus, which contains the Bird Flu, Spanish Flu, Swine Flu, and other flu outbreaks that seemed to get a lot of play in the media (although the Spanish Flu outbreak really was nasty). We all know how vaccines work – you get an inactivated virus, your body develops an immune response to it without getting sick for the most part. However, viruses may randomly mutate to where inactivated viruses may become, well, activated, and now you’re sick for real. Hope you’ve got your favorite chicken soup recipe handy.
(what, I like Phở, OK?)
In a study recently published in Science, a team of scientists from Peking University tried to make flu (for the rest of this post, ‘flu’ is me saying ‘influenzavirus A’) vaccines with live viruses that are unable to replicate. Wait, hang on, live!? Live, active flu, all up in your immune system? Really? Don’t panic, it’s something that’s been done before. See, attenuated viruses are live viruses that can still infect cells, but aren’t necessarily virulent, as in they don’t replicate and blow the cell apart as they normally do. This would give the body enough time to develop an immune response in the form of antibodies without making you that much sicker due to blown-up cells. Of course, part of the immune response includes secretory immunoglobulin A, which means you’re still going to have a lot of mucus.
Viruses work by hijacking the cell and overriding it with its own commands – namely make more viruses – by injecting it with RNA or DNA. Si et al. propose tooling around with the genome of the flu virus, introducing some genetic sequence in the virus itself so that the cell doesn’t read the whole thing, particularly the part where it tells it to make more and blow the cell. This is how they’re going to attenuate the virus – by making it ‘replication-incompetent’. They also hypothesize that this could inhibit the random mutation of Stupid Flu (that is my name for it, not theirs – Science would never allow that to make print), which makes sense since less replication means less chances for mutation. Of course, some testing has to be done to see if it actually works.
So does it? The authors found that Stupid Flu definitely infects like it should, but it didn’t even kill the lab mice, who were hit with 10 times the lethal dose for the normal, ‘wild-type’ flu (although spare a thought for the poor mice who were hit with 10 times the lethal dose of the wild-type flu). In addition, they found no evidence that the virus had mutated even under conditions where it could, such as exposure to what they call an ‘unnatural amino acid’ that we don’t need to go into. Now, the kicker: when compared to the inactivated vaccine that we’re used to getting, the Stupid Flu (fine, we’ll go with their name, the Premature-Termination Codon, ‘PTC’ viruses) generates more antibodies, similar to the attenuated, live flu vaccine. Kind of the point of this research, right?
There isn’t really a ‘cure’ for the flu, it’s really just giving your immune system better training materials for when flu comes your way. That way, when it does, you’re ready for whatever it brings you, and you can get back to not being under the influenza.
(but feel free to give yourself some TLC, though – someone has to)
Featured Article: Si L, Xu H, Zhou X, Zhang Z, Tian Z, Wang Y ,Wu Y, Zhang B, Niu Z, Zhang C, Fu G ,Xiao S, Xia Q, Zhang L, Zhou D. (2016) Generation of influenza A viruses as live but replication-incompetent virus vaccines. Science 354(6316): 1170-1173. doi: 10.1126/science.aah5869
Featured Image: Wikimedia Commons/Public Domain (Author: MSgt. Carlotta Holley, US Air Force)