A lot of people say a lot of things about COVID transmission risk. But what do the heavyweight experts in airborne infection and transmission control, who were in the game long before COVID, say? It’s not what you’d expect. A 🧵. Ladies first. Professor Lidia Morawska, Director of the International Laboratory for Air Quality and Health @QUT, has been awarded the highest honours in the field of aerosol science. She led the declaration that COVID is airborne; and has written more than 1,000 academic papers.

Dear National Cabinet,

I’m writing to ask that you go to bat for the health system’s youngest patients. Please postpone the axing of mandatory COVID isolation rules until thousands of clinically vulnerable little kids, who only got access to their first under-5s Moderna dose… last month, have had the chance to complete their primary vaccination series. It’s not too much to ask for children facing death or debilitation from COVID, due to severe immunocompromise, disability, or complex health conditions. Protecting them is paramount.

Failing to provide Covid mitigations for the general public, who face potential longterm harms, is negligence. Failing to provide them for the clinically vulnerable, who face probable death or debilitation, is a human rights violation. With non-fit-tested N95/P2s being about 20% leaky, with top quality N100/P3s and fit-testing being out of reach for most, and with approved kid-sized N95/P2s being non-existent, mask mandates are a human rights necessity. 2/

“The greater the infectiousness of the virus, the greater the infection-free ventilation needed to keep concentrations low. For Omicron, for example, 6-12 ACH ventilation, or equivalent air disinfection, may not be enough to prevent transmission.” time.com/6143799/covid-… “Unfortunately, not all transmission is preventable by air disinfection—for example, transmission at very close range where there is no time to remove or inactivate viruses generated by one person before they are inhaled by someone else.” (So we should all wear P2/N95s.)

The commentator spin on dropping mask mandates serves the business and political agendas that feed it, but completely misses the point. Letting it rip is tantamount to human rights violations against the clinically vulnerable. 1/

https://twitter.com/astrokatie/status/1500252663501496321?s=21

Here’s a 🧵 on the genocidal implications of dropping mask mandates, which exposes the clinically vulnerable to grave harm when they have to access unavoidable essential goods or services in public areas. 2/

https://twitter.com/glbabbington/status/1499946789394595844?s=21

By the will of Big Business, and in a bid to win elections, several governments have dropped mask mandates, thereby putting clinically vulnerable people on a conveyer belt to death or debilitation. 1/ The clinically vulnerable among us are babies, toddlers, preschoolers, school kids, uni students, service staff, tradies, professionals, the disabled, prisoners, daughters, sons, mothers, fathers, grandparents. 2/

When the pandemic began, the early modelling was based on default influenza assumptions, so they said we should shut the schools, because kids are germ factories. The early 2020 data showed us that kids weren’t really getting or spreading COVID, but in defence of that precious modelling, the kids who were hardest hit by school closures, and least affected by COVID, the 0-9 year olds, missed out on learning they’d never get back.

Interesting. As @jburnmurdoch pointed out, Omicron hospitalisations are accelerating faster, but are less severe (for adults), than Delta hospitalisations at wk 3 in the wave. Here, @dr_kkjetelina points out the low proportion of ICU cases might reflect the steepness of the wave.

https://twitter.com/dr_kkjetelina/status/1468424987845529604

That is, the proportion of cases we’ve seen thus far in the super-fast Omicron wave is smaller than the proportion of cases we’d seen at this point in the slower Delta wave. This factor alone could cause an unusually low proportion of severe/ICU at first, says @dr_kkjetelina.

An update from Professor Rudo Mathivha, paediatric critical care physician, and head of the ICU at Chris Hani Baragwanath Hospital in South Africa, the third largest hospital in the world. 1/2
For the first time in the pandemic she’s seeing toddlers, kids, and teens with moderate to severe symptoms, needing oxygen and other supportive therapies, and several days in hospital. She’s already lost an unvaxxed 15 year old with no risk factors for severe COVID. 2/2