[EvaH (OP)]

John asks:

Since two existing proprietary sprays (Vicks First Defence nasal spray and ColdZyme throat spray) appear effective in stopping or inhibiting the full development of the common cold coronavirus, if used prophylactically, is any work being done to determine whether these sprays, or the technical basis of their operation, can be used as a Covid-19 prophylactic?

Can you help?

[rhinegold]

I am sorry I have no means to find an answer to your question, but I can share our experience with you.

Since March 2020, our family has regularly used VICKS "Sinex Micromist" before leaving the home and returning afterwards. It has helped to cure my daughters runny nose over time, and contributed to our wellbeing factor, during these challenging month and days.

The product is very expensive here in the UK, but good health matters.

[Bored chemist]

I am sorry I have no means to find an answer to your question, but I can share our experience with you.

Since March 2020, our family has regularly used VICKS "Sinex Micromist" before leaving the home and returning afterwards. It has helped to cure my daughters runny nose over time, and contributed to our wellbeing factor, during these challenging month and days.

The product is very expensive here in the UK, but good health matters.

Good health isn't likely to be assured by not following the instructions on medicines.
The product information says you shouldn't use it for more than 7 days n a row.
https://www.boots.com/wcsstore/ExtendedSitesCatalogAssetStore/Attachment/Product_PatientLeaflets/10068168%20-%20Vicks%20Sinex%20MICROMIST%20NASAL%20Spray%2015ml%20PIL.pdf

So, regular use over "these months and days" is misuse.
The active ingredient; Oxymetazoline HCI 0.05% w/v reduces blood flow in the lining of the nose.
In doing so, it treats one of the symptoms of a cold.
It has no "protective" action- in fact it is likely to increase the risk of infection since part of the role of the mucous is defensive.
At the moment, all it is likely to be doing is preventing "rebound congestion".