Dr. Zeynep Tufekci had a May 7, 2021 NY Times essay that went into some depth on why the medical community got a key element of how Covid-19 spreads wrong for so long.
To make a long story short, size matters — specifically the size of the particles being spread by people infected with the virus. The initial assumption was that what mattered were just the droplets — particles large enough to settle fairly quickly. (One reason why there was so much emphasis on cleaning surfaces early on.)
While droplets were and are a hazard, the real problem is the smaller particles, referred to as aerosols. They remain in the air and float farther — and they seem to be the primary way the virus spreads. This matters.
If the importance of aerosol transmission had been accepted early, we would have been told from the beginning that it was much safer outdoors, where these small particles disperse more easily, as long as you avoid close, prolonged contact with others. We would have tried to make sure indoor spaces were well ventilated, with air filtered as necessary. Instead of blanket rules on gatherings, we would have targeted conditions that can produce superspreading events: people in poorly ventilated indoor spaces, especially if engaged over time in activities that increase aerosol production, like shouting and singing. We would have started using masks more quickly, and we would have paid more attention to their fit, too. And we would have been less obsessed with cleaning surfaces.
Our mitigations would have been much more effective, sparing us a great deal of suffering and anxiety.
A great deal of time and energy went into blocking transmission based on the idea of controlling for droplets, instead of focusing on ventilation and keeping people from indoor environments that facilitated spread by aerosols.
Part of the problem was institutional; the medical profession had been trained to regard droplet transmission as the most likely route of infection.
The omission is not surprising. Throughout the pandemic, the W.H.O. was slow to accept the key role that infectious particles small enough to float could be playing.
Part of the problem is that correlating particle size with ability to stay suspended in air was based on faulty numbers.
...the upper limit for particles to be able to float is actually 100 microns, not five microns, as generally thought. The incorrect five-micron claim may have come about because earlier scientists conflated the size at which respiratory particles could reach the lower respiratory tract (important for studying tuberculosis) with the size at which they remain suspended in the air.
It is also an inherent problem that findings that challenge established assumptions require a high level of proof to be taken seriously — experts don’t like to see their expertise overturned. Once the initial assumptions were codified into practice, modifying them in the face of new evidence proved extremely difficult, although some countries got it right.
Dr. Tufekci cites a number of studies that found aerosols were the mechanism driving transmission — and the institutional resistance to those findings. It didn’t help that the public was confused by guidelines that kept changing, that contradicted earlier ones.
The confusion over not needing to wear masks early was based on the mistaken assumption that droplets were the danger — which could be mitigated simply by staying farther away and cleaning surfaces.
Read The Whole Thing if you can get past the paywall — Dr. Tufekci has a lot of information that boils down to this:
It’s true that as the evidence piled on, there was genuine progress and improvement, especially as of late. Even before the change in language last week, for example, the W.H.O. published helpful guides on ventilation, first in July and updating it in March. Recently, though the organization’s documents have lagged, more of its officials have started giving advice compatible with aerosol transmission, emphasizing things like close mask fit — which matters little for droplet transmission — and ventilation — which matters even less. All this is good, but nowhere near enough to change the regulations and policy bundles that had already been put in place around the world.
And the progress we’ve made might lead to an overhaul in our understanding of many other transmissible respiratory diseases that take a terrible toll around the world each year and could easily cause other pandemics.
(Besame in comments links to a twitter thread that covers what the NY Times essay is all about in more detail. )
Along with this, there must be effective actions to restore the credibility of the institutions like W.H.O. that got things wrong for so long, and education of the public to understand how difficult this has been without feeding into conspiracy theories.
It needs to begin a campaign proportional to the importance of all this, announcing, “We’ve learned more, and here’s what’s changed, and here’s how we can make sure everyone understands how important this is.” That’s what credible leadership looks like. Otherwise, if a web page is updated in the forest without the requisite fanfare, how will it matter?
As long as people refuse to wear masks, as long as people refuse to get vaccinated, as the pressure to reopen grows without understanding the actions needed to do so safely, we’re still going to be in trouble — and it’s trouble we are going to have to learn to live with.
It appears Herd Immunity is not an option
The latest consensus is that herd immunity is not going to be attainable, not in the U.S. and not in most of the world. The hope was that spread of the virus could be brought down to a level where it would die out once cases became too few to support continued transmission. That now seems unlikely.
Experts now say it is changing too quickly, new more contagious variants are spreading too easily and vaccinations are happening too slowly for herd immunity to be within reach anytime soon.
That means if the virus continues to run rampant through much of the world, it is well on its way to becoming endemic, an ever-present threat.
Virus variants are tearing through places where people gather in large numbers with few or no pandemic protocols, like wearing masks and distancing, according to Dr. David Heymann, a professor of infectious disease epidemiology at the London School of Hygiene and Tropical Medicine.
Going forward, the likely scenario is that Covid will remain a threat that has to be managed like other endemic diseases. Surveillance and testing will be critical, as will responding to outbreaks with the proper measures. Ventilation will need more attention, just as we pay attention to water and sewer issues for waterborne diseases.
To what extent continued wearing of masks and other precautions will be prudent will depend on an individual’s risk factors and prevalence of infection in a given location. Periodic inoculation with vaccines updated to deal with new variants will probably become necessary — which has implications for public health and healthcare systems around the world.
The Death Toll Keeps Rising
Digby picks up on the horror in India: “You Can’t Ignore The Dead”. The reported infection rates and death tolls do not match up with the actual body count.
Dr Ashish K. Jha on the horror unfolding in India:
India reports another 400,000+ cases, 4000+ death day
A sustained level of horribleness
And its not correct
True number surely closer to 25,000 deaths, 2-5 million infections today
Lots of ways to estimate but here’s a simple one
Look at the crematoriums
Dr. Jha goes on to explain why the reported numbers don’t add up. It’s not just a problem in India either. NPR reports “New Study Estimates More Than 900,000 People Have Died Of COVID-19 In U.S.” — and the higher toll is global.
A new study estimates that the number of people who have died of COVID-19 in the U.S. is more than 900,000, a number 57% higher than official figures.
Worldwide, the study's authors say, the COVID-19 death count is nearing 7 million, more than double the reported number of 3.24 million.
The analysis comes from researchers at the University of Washington's Institute for Health Metrics and Evaluation, who looked at excess mortality from March 2020 through May 3, 2021, compared it with what would be expected in a typical nonpandemic year, then adjusted those figures to account for a handful of other pandemic-related factors.
The final count only estimates deaths "caused directly by the SARS-CoV-2 virus," according to the study's authors. SARS-CoV-2 is the virus that causes COVID-19.
Getting a handle on this is critical. Without accurate numbers, it’s impossible to tell how effective control measures are. When and where resources are limited, it is important to maximize how effective their use is and that requires good information.
Assuming my math is correct, for the long term seven million deaths out of a world population somewhere near 8 billion is roughly .089%, which may not seem like a big deal in absolute terms. But, it is continuing, it is not a good way to die, it is a costly way to die — and it’s a warning sign.
A world where the climate crisis is worsening is going to see rising death rates from climate events and their consequences. This will constrain resources and destabilize governments. A world with a growing population that is putting more and more pressure on the remaining natural environment is going to see more emerging infectious diseases.
We have yet to demonstrate we are smarter than bacteria in a Petri dish which continue to multiply until they use up all of their nutrients and die in their own accumulating wastes.
Buckle your seatbelts — it’s going to be a bumpy ride.