I have two 12 weeks old kittens, who've been with us for 2 weeks now. When we got them they appeared a little poorly (I know, I should not have taken them when they are ill, but I did and that's that). Took them to thevets they both had a upper respiratory infection. The vet prescribed antibiotics which they have finished now.

Today when they went to the vets they still have "mild flu" this is preventing them from being able to get their kitten vaccinations. The vet told us to wait 3 more weeks and see if it clears up and gave eye drops for the conjunctivitis

Is there any way I can help speed up the process?

I'm currently switching their food to a premium brand (Nature's Menu with some James Wellbeloved dryfood) from Whiskas kitten food. Hopefully that will help a little, I do bathe their eyes with cotton wool and water at least once a day to clear the gunk away.