Alternative measures may include rinsing the palate with cold water frequently, (the pollen is harmless in the tummy), splashing cold water into the eyes frequently, vaseline around the nostrils, (to trap the pollen), and taking sensible measures such as showering and changing clothes following exposure to pollen. Shutting windows at night may also help.
A stage up maybe to consider topical treatment (nasal spray and eye drops seem to work well)-ask your AME.
Antihistamine treatment has been debated at length previously-(try a search). Second generation treatments claim not to cause drowsiness, but some users beg to differ.
The "shot" I think you may be referring to is
kenalog. You'd be hard pushed to find a prescriber in the UK insured to offer it, as it can rot your bones. (Although it does work very well for hay fever).
Safe flying
