Will my sprouts recover from mealy aphid infestation?

For the first time ever my brussels sprout plants have been badly infested with mealy aphid.  They didn't appear until the plants were already quite big (about a metre high).  I've given them a good spraying today with a pyrethrum spray ("Bug Clear Gun for Fruit and Veg").  I'm hoping that'll sort them but can anyone tell me whether the plants are likely to recover or will I have lost them?  They're well netted so I'm hoping the little beasts won't migrate to the other brassicas, but should I spray those as well just in case?

I think there is a good chance of recovery if you have managed to kill all the blighters. I have had these on my swede plants this year, and they are now growing normal shaped leaves again, so I hope the same will be true of your sprout plants