[entee]

I don't think that's quite right. Even if you have a flu strain with a particular name (H1N1) there are a number of variants within the H1 and/or N1 proteins that the vaccine will be targeted to as well, so the number is quite a bit larger than 198/131.

It's not that hard to make a new vaccine, the process for flu is very accelerated because they're just a variation on the original theme which has been proven to be safe (though unclear on effective until AFTER the flu season hits). If you think about it, we make a new flu vaccine every year, and develop it in 6 months. Each one contains a few guesses as to which of the flus are going to be an issue, it's not just one antigen in the vaccine. Those guesses are just that, an informed prediction, which is why the vaccines tend to be fairly ineffective (40-60%) at preventing disease altogether, though perhaps better at preventing serious disease.

Moderna is claiming to be quicker, so they'd have a more accurate read on what the REAL flu strain this year is going to be, and so it should be more efficacious. The key variable will be dosing. mRNA vaccines can only deliver a certain amount of mRNA so it might be impractical to deliver very many antigens at once. Also delivery issues, the current flu vaccine is super easy to make and deliver to patients, mRNA vaccines with their complicated cold chains aren't. Obviously it's not an impossible problem, but it's less convenient.

Time will tell, it's certainly very promising!

Helpful: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3619640/

[roywiggins]

It would be especially worth it to have approved mRNA flu vaccine in hand for the next pandemic flu. You'd might be able to actually vaccinate your way out of it.