Originally Posted by tatsu15
What can cause a virus to mutate? I am wondering because my doctor was insisting I get the H1N1 vaccine and I declined. She said she got the H1N1 flu herself and it was pretty bad. So I jokingly said to her well at least you are immune to it. And she said it's mutating. She was one case of the H1N1 virus mutating.
So in my mind I thought what could have caused it to mutate? Was it the H1N1 vaccine itself since they do use genetically altered viruses. I guess I was comparing the virus mutation to some types of bacteria that are resistant to antibiotics because the mutated as well.
Well, the flu is known for its ability to mutate. I mean, they tend to mutate really easily which is why everyone was freaking out - easily passed virus + deadly mutation = scary scenario. However... for the same reason that getting the virus itself (and the natural immunity that way) won't necessarily cover you for immunity to a mutated virus, the vaccine won't work either. They're using the same (supposedly extremely stable) virus. There was talk of a mutation in the Ukraine, but it looks like that's not what really happened, they just had other issues with their medical situation and some hysteria based on the political situation there, I guess.
Anyway, the flu viruses mutate pretty much every year, which is why they have an annual flu vaccine with different viruses in it... mutated forms of previous viruses, I believe (and the occasional new one). But viruses just replicate very fast, and mutations are just random changes in the dna - most of them are useless and the organism can't function, but occasionally a "good" mutation happen to the organism that makes it function *differently* - sometimes it's more dangerous to us, and sometimes less. Generally, though, unless the mutation affects the "H" or the "N" (as in H1N1) proteins that are part of the coat, we should still keep immunity if we have it (if I understand this right) because those are the things that our immune system recognizes... when those change is when suddenly we're back to being without immunity, but I could be wrong.
Mutation just means a random change in the dna that caught on and spread, essentially, because it was an effective change for the VIRUS. Something that I *have* heard may be causing changes to the virus is the overuse of Tamiflu creating tamiflu resistance. Not that tamiflu was apparently overly effective anyway, if you look at the recent studies coming out about it.
Beyond that, though, they keep commenting on how remarkably stable this virus is - which is actually why the vaccine was useful at all... and why those over 60 yrs may have some immunity to it - from an outbreak way back in the day. With the number of people the virus infected over the course of the Southern flu season, there was a decent statistical probability of seeing some mutations that made the vaccine completely useless, but that's not what happened.