Strict (absolute) Mask Mandates
Subsequent positivity rates compared to that in nations without mandates
One reason that officials might give when telling people to “mask up” is that the masks are supposed to cut the spread of COVID. On this view, getting COVID is a bad thing, and should be postponed for as long as possible, rather than letting people develop natural immunity to it.
But the original reason given, that masks cut spread, does not have good data backing it. In this substack, 28 nations that had ultra-strict (absolute) mask mandates on 21 Aug 2021 were compared with 5 nations that had no mask mandates.
Because people who are positive for COVID can remain positive for about 5 weeks, a 5-week interim was allowed to pass before checking for the percentage of all COVID tests that come back positive (the most-objective indicator of COVID spread).
By waiting 5 weeks, it guarantees that the full protective effect of masks will have occurred, and that no people who had already been positive on 21 Aug 2021 were carried over into the observation window.
Regarding the median spread of COVID, as measured by “% positivity,” masks doubled the amount of COVID spread:
[click to enlarge]
The orange cells represent positivity rates of 60% or higher (6 of every 10 COVID tests performed came back positive).
In cell I33, you have the ratio of median positivity rates for “mask mandates versus no mandates” — showing how the median spread of COVID in nations with mask mandates was more than twice the median spread of COVID in nations without mask mandates.
Median test positivity was 8% (cell D33) in nations with strict mask mandates, but only 4% (cell K11) in nations without mask mandates. The ratio of the mean positivity rates was even higher (making mask mandates look even worse).
Mongolia (row 19) is an outlier. With strict mask mandates, there was still 77% COVID positivity 5 weeks after the date that was used as a baseline. Even more crazy, positivity broke the 99% barrier under Omicron (99% of tests came back positive for COVID).
Because you can only ever have 100% positivity at most, this implies that masks cannot possibly reduce the spread by even 1%. You’d never see a mandated nation with over 99% positivity if masked reduced spread by, say, 2%.
If masks cut transmission by 2%, then the highest postivity that you would ever be able to see would be 98% (assuming 100% spread in the absence of masks).
Evidence suggests that, not only do ultra-strict (universally-required) mask mandates fail to prevent the spread of COVID, they appear to increase the spread of COVID.
Reference
[Levels of mask requirements; 0 & 1 = not required; 4 = universally required] — OWID. https://ourworldindata.org/covid-face-coverings
[COVID positivity rates] — OWID. https://ourworldindata.org/coronavirus-testing
[mean positivity duration is 2 weeks, with a standard deviation of 1 week] — Kojima N, Roshani A, Klausner JD. Duration of COVID-19 PCR positivity for Omicron vs earlier variants. J Clin Virol Plus. 2022 Aug;2(3):100085. doi: 10.1016/j.jcvp.2022.100085. Epub 2022 May 21. PMID: 35615055; PMCID: PMC9123744. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9123744/