The thing I find most baffling is that we have very good reason to believe [1] that HEPA air purifiers can keep the air clear of the virus, and yet they are barely talked about.
In the UK we're still waiting on results from trials in schools [2] and we've barely started running trials in care homes [3], and this is 2 years in. In March 2020 our government was trying to comission Dyson to mass produce medical ventilators of questionable use for emergency, and yet we never really tried to get them to mass produce something that is their core competency and put it in classrooms and care homes.
HEPA filters are unobtrusive and can be made quite silent by using larger fans. Its mind boggling enough that we're barely using them, but its even more mind blowing that we have no trial data for them 2 years in.
There is also reason to believe they would work synergically with masks. All masks leak [8], some more than others - portable HEPA devices should take care to limit the (cumulative) effect of leakage to a minimum. Especially in indoor spaces where people spend long amounts of time, and especially in winter as well as in these "modern" business buildings with windows that don't open.
So why does this matter? Mainly because we keep pretending long covid doesn't exist. In the UK, ONS esimates that a 1.3 million (2% of the population) [4] people report long term symptoms, of which 1/2 million (nearly 1% of the entire population) have had them for 1 year or longer, with 247,000 (20%) reporting that their ability to undertake their day-to-day activities had been “limited a lot”.
Information on vaccine protection from long covid has been conflicting [5], with some studies showing they enable return to baseline [6] while others showing almost no effect [7].
Additionally, since Omicron is so new, we don't (and cannot) have any long covid data on it.
It therefore makes sense to continue limiting spread and focus our effort on understanding long covid risk, prevention and treatment better, before completely lifting all restrictions. Especially if it can be done with the help of tools that are almost completely unobtrusive, such as portable HEPA filters.
[1]: https://www.nature.com/articles/d41586-021-02669-2
[2]: https://www.leeds.ac.uk/news-health/news/article/4953/can-ai...
[3]: https://www.bristol.ac.uk/news/2021/october/airfilter-study....
[4]: https://www.ons.gov.uk/peoplepopulationandcommunity/healthan...
[5]: https://www.nature.com/articles/d41586-021-03495-2
[6]: https://www.medrxiv.org/content/10.1101/2022.01.05.22268800v...
[7]: https://www.medrxiv.org/content/10.1101/2021.10.26.21265508v...
[8]: https://www.pnas.org/content/118/49/e2110117118#:~:text=Medi...