German study shows promising results in infection reduction (not just for Covid but also for other respiratory viruses) using a hayfever nasal spray:
A two-thirds reduction in the risk of infection in the clinical study with 450 healthy adults, the active ingredient azelastine, which is contained in Ursapharm's hay fever spray Pollival®, was tested. "Our results show that the 227 participants who regularly used the azelastine nasal spray had a reduced risk of contracting corona infection by about two-thirds compared to the 223 participants who were treated with a placebo alone," says Professor Dr. Dr. Robert Bals.
https://www.eurekalert.org/news-releases/1096684
Article in German:
https://www.saarbruecker-zeitung.de/saarland/saarland-heuschnupfenspray-schuetzt-gegen-corona-und-das-ist-noch-nicht-alles_aid-134126961
An equivalent product is available in Aotearoa:
https://www.dymista.co.nz/en-nz/product/dymista
https://www.medsafe.govt.nz/Consumers/cmi/d/dymista.pdf
Dymista has 125mcg of active ingredient vs 140mcg in the German product. Apparently, it's most effective at 5 doses/day.
The best deal I've found is $38/17ml bottle at:
https://www.pharmacydirect.co.nz/Dymista-Nasal-Spray-120-Dose