Vindication and its Implications: Airborne Transmission

Prepare for the worst. Hope for the best.

By Tom Lawton – May 8, 2021

This is meant to be a post celebrating the WHO’s recent U-Turn, while acknowledging its lateness as an insult to the scientific community’s nominal intention to seek truth, leading to a resounding call to (finally) update restrictions in light of the not-so-new theory of transmission.

But, as it turns out, there are two parties vindicated by recent events, not one (though in reality they overlap significantly in membership). Yes, there are the scientists/activists/citizens who were ahead of the curve in following the trail of evidence, and departing from 'scientific’ consensus even before it had worn out any claim to credibility. Compelling evidence against the initial hypothesis that airborne transmission is non-significant in the spread of Sars-Cov-2 has existed at least since the latter end of 2020, see the article in Lancet, Covid-19 Transmission – Up in the Air, published in October.

Their’s was the injury to the 'science’ the WHO claims to champion, and in this case (it just so happened) people’s lives were in the balance.

Yet the first and foremost harm was done to another party: our collective grandmother. That is, all the survivors who double as preachers of common-sense when they’re not baking, fixing things for their kids, or being lectured by their snot-nosed grandchildren. Keeping them company were the 200 scientists who in July 2020 issued a statement calling on policymakers to adapt their guidelines to better safeguard against possible airborne modes of transmission. Adopting policies that assumed no significant role for airborne transmission (when the point was still in doubt many, many months ago) acted against common-sense and directly jeopardised public safety; failing to acknowledge the weight of evidence pointing to airborne transmission once it had arisen (again, many months ago) added insult to injury and delayed the necessary course-correction in policy.

There were always two ways to get to the policies that guard against the worst case scenario we now confront. This piece is being written after policymakers worldwide have taken (and some continue to take) the path that uses our lack of knowledge as an excuse for being unprepared: that of waiting for a shift in our understanding of the mechanisms underlying transmission that places the worst case scenario into the same category as the most probable, and then waiting some more, before making the necessary preparations to deal with it.

Your grandmother will tell you for free what is wrong with this approach: 'it’s better to mistake a stone for a bear than a bear for a stone’, or ’better to be safe than sorry’.

No matter the uncannily rock-like features of the supposed bear even at relatively close range, an animal operating more intelligent regions of its brain than policy-makers ever engage will approach assuming they’re walking towards a great, hulking carnivore until this is (thoroughly) disproven. This, at a collective level, is referred to as a violation of the precautionary principle: the mandate to avoid behaviours that may expose us to systemic risks even (and especially) when our knowledge is insufficient to measure said risk. Most policymakers have done the reverse to the canny prey, and gone beyond 'animal stupidity’. In fact, in first waiting for confirmation that masks are effective in order to endorse universal masking, and then that the virus is airborne get sufficiently strict about ventilation and social distancing, they’ve done the equivalent of walking right up to a sleeping bear, poking it with a stick, and taking skin and saliva samples to perform sediment analyses before deciding to freak out. I’m being kind: there are those worldwide who are still adopting the 'it’s a rock’ hypothesis; these individuals were recently promising a 'return to normality’ in the UK while prophesying that a third wave would inevitably encroach upon British soils, without acknowledging the likely connection between the two outcomes.

But it would be hypocritical for me to enjoy the analogies too much. I hadn’t comprehended the full gamut of public health implications aerosol transmission implied: since the start of the pandemic, I’ve been wearing a loose-fitting bandana while walking the dog (and indoors with family members) and stupidly failing to give thought to the idea that it might be significantly less effective than using a tight fitting mask. But the smaller size of aerosols relative to the droplets originally, and wrongly assumed to drive infections, in addition to the observation that loose coverings fail in preventing viral particles from being dispersed into the air from the sides of a person’s head, means that fitting is considered essential in environments where the risk of transmission is at its highest (hence the new guideline to provide HCWs with (minimum) N95 respirators: 95 because the design filters 95% of airborne particles).But the news that Covid is airborne doesn’t change (late-adopted) best-practices where masks are concerned: it just puts another superfluous nail in the coffin of the resistance to universal masking which still holds in a variety of institutions (including schools) in a variety of countries around the world. Simply put, masks are, and always were, essential in reducing transmission of the virus by filtering airborne particles.

Indeed, they are disproportionately more effective when any two people that come into contact are both wearing masks. The compounding efficacy of masks when used by multiple individuals interacting is the principal reason universal masking has always been needed to address the possibility (now probability) of airborne transmission.

The other key issue is ventilation, through open windows wherever possible and artificially through air purifiers (APs) and air cleaners, aka non-portable mega-APs. Without ventilation, airborne viral particles typically remain suspended for several hours, and uniformly disperse, meaning that social distancing guidelines advocating 6m between people are ineffective in protecting individuals from dangerous viral loads in indoor environments. (Indeed, the fact that the virus spreads in aerosol form means that the 6m guideline is outdated in most contexts; aerosols can travel tens of meters before settling). Further, in an unventilated space where people are repeatedly coming and going, the volume of suspended viral particles will obviously accumulate; so that in busy spaces where air has been recirculated for several hours newcomers are likely being exposed to dangerous viral loads as soon as they enter, no matter where they’re standing in relation to others!

I can’t speak for methods of assessing the need for ventilation. CO2 monitors are widely praised for use in those rooms where nobody feels like taking an unmasked whiff of the air to see whether it qualifies as 'musty’ to them. If that isn’t an antiquated recommendation in light of the not-so-recent revelation that Covid is airborne, I don’t know what is.

Neither can I speak personally for air purifiers, because I don’t use them. But it isn’t hard for me to see their potential application to my circumstances, despite my being unemployed and ostensibly cut off from the human race for the last 12 months. During the winter I was unable to persuade my grandmother to open the windows, with her fearing, or citing a fear of, pneumonia as a greater threat to her health than Covid-19 when mixing with working family members. And I remember my trepidation using my local vet surgery after discovering that the only means of ventilation of one of the two rooms hwere pets are frequently examined was the door adjoining it to the main room, where the main room itself, small and often busy, seemed to be primarily ventilated by the sporadic opening of the front door.

Even as we go into summer, in the UK the weather is fickle, and I speculate there will be many reluctant to voluntarily utilise natural ventilation in a variety of contexts where airborne transmission is likely to be prolific in its absence, like my vets, and others where adequate ventilation is difficult to achieve by other means, even when people are willing to put up with a draft. From the outside, air purifying technology, especially air cleaners, which filter air for much larger spaces more efficiently, would seem to have obvious use along with natural ventilation methods, but its virtues are for its users to extol.

Finally, avoidance of crowding. We can’t afford further superspreader events, and crowds are their principal generators. I’m sympathetic to the danger this poses in hamstringing the ability of activist groups to organise in opposition to their governments, which is another reason for much greater stringency in the short-term, that such groups can enjoy greater latitude over the long-term and keep governance (broadly) on track without risking public health by exacerbating the contagion.

Meanwhile, I’ll be wearing category-1 reusable masks (no bandana) when outdoors, and indulging the luxury of politely treating others like lepers as long as I’m searching for work. I hope everyone else is soon granted the opportunity (or mandate) to do the same for the time necessary to reach zero transmissions, irrespective of their employment status.

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