Various papers :
Lifting mask mandates leads to more Covid :
https://www.medrxiv.org/content/10.1101 ... 1.full.pdf In February 2022, following the rescinding of a Massachusetts statewide school masking mandate, only two cities (Boston and neighboring Chelsea) out of 79 school districts in the greater- Boston area, maintained masking requirements in K-12 schools. This provided an opportunity to examine the impact of removing masking on COVID-19 case rates among students and staff in the public-school setting.....
Before the statewide school masking policy was lifted, there was no statistically significant difference in case rate trajectories between school districts. However, weekly and cumulative case rates were significantly higher in students and staff in school districts that removed masking requirements, compared to districts that had not yet lifted requirements. We estimate that lifting of school masking requirements was associated with an additional 44.9 (95% CI: 32.6, 57.1) COVID-19 cases per 1,000 students and staff over the 15 weeks since the lifting of the statewide school masking requirement, representing nearly 30% of all cases observed in schools during that time.Model suggests ventilation of 10l/s indoors cuts the risk to the same as outdoors :
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8652937/ The model considers the involvement of exhaled droplets with initial diameter ≤50 µm in the short‐range airborne route, whereas only a fraction of these droplets with an initial diameter within 15 µm or equivalently a final diameter within 5 µm considered in the long‐range airborne route. One surprising finding is that the room ventilation rate significantly affects the short‐range airborne route, in contrast to traditional belief. When the ventilation rate in a room is insufficient, the airborne infection risks due to both short‐ and long‐range transmission are high. A ventilation rate of 10 L/s per person provides a similar concentration vs distance decay profile to that in outdoor settings, which provides additional justification for the widely adopted ventilation standard of 10 L/s per person. The newly obtained data do not support the basic assumption in the existing ventilation standard ASHRAE 62.1 (2019) that the required people outdoor air rate is constant if the standard is used directly for respiratory infection control. Instead, it is necessary to increase the ventilation rate when the physical distance between people is less than approximately 2 m.Massachusetts is no longer seeing excess mortality from Covid since widespread vaccination, it's decoupled from Covid cases and hospitalisations :
https://www.thelancet.com/journals/lani ... 73-3099(22)00547-3/fulltext
In the 18-week period after BA.2, BA.2.12.1, BA.4, and BA.5 subvariants became prevalent (week ending Feb 27, 2022; appendix pp 2–3), there have been 0·1 excess deaths per 100 000 person-weeks, corresponding to 134 excess deaths (95% CI –921 to 1189; appendix pp 2–3), despite at least 226 857 newly recorded cases, as evidenced by corresponding substantial spikes in SARS-CoV-2 wastewater levels and changes in testing volume (appendix pp 2, 4–5). This value corresponds to a 97·3% reduction in excess mortality compared with the 8-week initial omicron (B.1.1.529) wave, during which excess mortality was 4·0 per 100 000 person-weeks (2239 excess deaths; 95% CI 1746–2733), and a 92·7% reduction in excess mortality compared with the combined 26-week delta (B.1.617.2) and delta-to-omicron transition periods, during which excess mortality was 1·5 per 100 000 person-weeks (2643 excess deaths; 95% CI 1192–4094). However, new COVID-19-associated hospitalisations continued to occur during this period (figure B), either reflecting background community prevalence or that new COVID-19 cases were less severe or exacerbated chronic medical illnesses enough to require emergency care but not to cause proximate mortality.And if you combine masks, vaccines and ventilation you could get very low infection rates indeed during the delta wave :
https://jamanetwork.com/journals/jamane ... le/2794964All mechanically ventilated classrooms had MERV-13 (minimum efficiency reporting values) filter upgrades and settings maximized to allow for increased fresh air and a minimum of 2 to 4 air circulations per hour. Non–mechanically ventilated classrooms had windows open when outdoor temperatures allowed and commercial-grade HEPA (high-efficiency particulate absorbing) filters placed within the rooms....
COVID-19 vaccination was mandated as of September 2, 2021, allowing for religious or medical exemption....Vaccination rates for BU faculty, staff, and students respectively were 98.5%, 93.5%, and 98.7%. Masking was mandatory during in-person instruction, but social distancing was not enforced. We analyzed SARS-CoV-2 transmission beginning September 1 to December 1, 2021, which was just prior to the end of term and the beginning of finals. During this time there were more than 140 000 in-person class meetings. Class sizes ranged from 2 to over 400 individuals (mean class size, 31 students)....
In total more than 600 000 SARS-CoV-2 PCR tests were conducted; of these approximately 896 (0.1%) of these tests showed detectable SARS-CoV-2. The 7-day rolling mean average ranged between 4 and 27 daily cases for most of the semester with a dramatic increase the last week of November... Of more than 140 000 in-person class events and a total student population of 33 000 between graduate and undergraduate students, only 9 instances of potential in-class transmission were identified, accounting for 0.0045% of all classroom meetings.Meanwhile the Telegraph got terribly excited about the persistence of excess mortality in England in the last year, claiming it was some kind of persistent effect from lockdown per se. Stuart McDonald of the Covid-19 Actuaries group dismisses that :
https://twitter.com/ActuaryByDay/status ... 1637472256So what are the underlying causes? I think three main factors:
1. elevated cardiovascular risks after covid infection
2. current delays for urgent treatment in the NHS
3. missed and delayed diagnoses early in the pandemicThe ever-excellent John Burn-Murdoch of the FT links it directly to the ongoing collapse of A&E care :
https://www.ft.com/content/f36c5daa-9c1 ... b26508b9d2Between July and December 2021, England recorded 24,000 more deaths than in a typical year, but only two-thirds of these could be attributed to Covid. And this year, less than half of the 10,000 excess deaths accrued since May were Covid-related. In total, there have been just over 12,000 additional non-Covid deaths across the two periods....
A 2022 British Medical Journal study found that the risk of death in the month following A&E attendance was 16 per cent higher for those who waited over 12 hours than those seen within four. By combining this with data first reported in the Independent on the long waiting times currently seen in NHS emergency departments, it is possible to estimate how many of the extra deaths may be the result of the A&E crisisHis Twitter thread goes into more detail - for instance Iberia has seen excess mortality, but it's probably related to their heatwave :
https://twitter.com/jburnmurdoch/status ... 2172873728