“Pandemic anxiety has turned lately to the question of viral evolution—the possibility that the disease might be outracing our efforts to contain it.” Of all the new strains, the Brazilian variant may be most concerning. (1/x) nymag.com/intelligencer/…
“In the Amazonian city of Manaus, where antibodies had been previously estimated in 76% of the population, there has been a horrifying and deadly dramatic second wave, right in the middle of Brazilian summer in a place believed to have already developed true herd immunity.”
“A new ‘Comment’ published Wednesday in the Lancet surveys what we know about the Manaus variant, and offers four possible explanations for what has happened there. None of them are good. Three are quite terrifying.”
“The first possible explanation is the most optimistic one: Perhaps that 76 percent finding was wrong, and many fewer people in the city had been exposed to the disease than that much-talked-about study suggested.”
“Even before the second wave, there were some indications that the estimate — which was based on mathematical modeling on top of a basic sample set — might have been high: 76 percent would have been above a crudely estimated herd-immunity threshold of 67 percent.”
“But herd-immunity estimates are rarely precise; even when you have the numbers precisely right, there is always a risk of ‘overshoot,’ and nearby Iquitos, in Peru, registered a similar attack rate of 70 percent.”
“The true observed seroprevalence in the earlier survey, which was adjusted upward to reflect antibody waning, was 52 percent, and even taking that lower-bound estimate, should have produced significant-enough protection to prevent an outbreak like the city’s second wave.”
“The second possible explanation is that the immunity measured by that earlier survey may already have waned — meaning that at least some significant group of those people estimated to have immunity in October had become vulnerable to infection again.”
“Among other things, this would suggest that at least some of those infected in early waves not just in Wuhan, Lombardy, New York, and London may be again vulnerable to infection already.”
“A third possible explanation is that the new variant, like those discovered recently in the U.K., South Africa, and California, is more transmissible than the strains that have dominated the pandemic thus far.”
“This would mean both that the level of acquired immunity in the population would have to be higher to offer herd immunity protection — perhaps north of 80 percent — and that the disease might be working much more quickly through that relatively small slice of the population.”
“The scariest of the possible explanations is even worse — that the new strain has achieved a more total ‘immune escape,’ meaning that it could evade antibodies produced by exposure in the first wave and infect again, even those people who’d mounted a robust immune response.”
“This is scarier than the possibility of waning transmission, because at least under that theory, antibodies offer protection for a period of time; and it is scarier than enhanced virulence, because it doesn’t just mean that those without antibodies are at heightened risk.”
“Instead, it would mean that existing antibodies could offer little protection, or perhaps no protection at all, with the disease progressing through the community a second time just as quickly and devastatingly as it did the first.”
“In other words, in theory at least, it could mean reducing what appeared to be a well-protected community into a virgin population—and would represent a threat of that kind to any community, anywhere in the world, should the Brazilian variant arrive, as it now has in Minnesota.”
“These hypotheses are not mutually exclusive, the authors point out — the new surge could be multiply determined. But whatever is driving it, the picture is scary.”
“A hospital that was overwhelmed in ten days in the spring became overwhelmed, this time, in just 24 hours, the Washington Post reports. Hospital patients arrived at the hospital sicker than in the first wave, ‘their lungs chewed up with disease.’”
“Local doctors insist the disease is not just more transmissible now but also more severe — and the data show that the epidemic is bigger this time than the first wave.”
“As anxiety about the new variants has mounted, those hoping to strike a tone of reassurance have pointed to evidence suggesting that, while vaccines may produce a somewhat less robust response against the new variants, they did produce what appears to be a sufficient response.”
“But pull back and the picture grows more concerning — and indeed reveals our focus on vaccine efficacy as a bit of global North narcissism.”
“A forecast published this week by the Economist Intelligence Unit suggested that most of the world’s poor countries are unlikely to reach mass immunization through vaccination before 2024 at the earliest, and may never get there.”
“If the Manaus experience is explained by waning antibodies, that could mean that nations in the developing world would pass through six or eight full pandemic cycles before vaccines arrive at scale.”
“If it is explained by immune escape, the path forward would not necessarily be quite so brutal...”
“It would mean that this variant evolved to evade previous antibody protection, and would tragically reset the clock on all naturally acquired immunity wherever it traveled, but in the absence of additional new strains populations would have to start from scratch...”
“...but could build up natural immunity over time.”
“Of course there will almost certainly be more variants coming over those next three years as well.” (X/x)

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More from @dwallacewells

20 Jan
The world has emitted a quarter of all the carbon it has ever produced in the twelve years since Joe Biden was inaugurated as vice-president in 2009.
Since 2009, and the last time a Democratic president was inaugurated, about 400 billion tons of carbon have been emitted into the atmosphere.
Back then, there were 386 parts per million of carbon in the atmosphere, 36 above the "safe" level of 350 ppm. Today the figure is 414.
Read 5 tweets
19 Jan
Climate change is much bigger than the U.S., and addressing it much more complicated than electing a new president. But on the eve of the inauguration, a thread to show just what a different world the new president is inheriting. (1/x) nymag.com/intelligencer/…
"The price of solar energy has fallen ninefold over the past decade, as has the price of lithium batteries, critical to the growth of electric cars."
"The costs of utility-scale batteries, which could solve the “intermittency” (i.e., cloudy day) problem of renewables and help power whole cities in relatively short order, have fallen 70 percent since just 2015."
Read 18 tweets
26 Dec 20
The alarming lead story in the New York Times this morning concerns the growth of COVID-19 through Africa, where the cumulative death total from the disease is less than 45 per million. In the U.S. it is 975 per million—more than 20 times worse. nytimes.com/2020/12/26/wor…
The story is primarily about caseloads, since the age structure of Africa means the disease has been much less lethal there.
While official counts underestimate the number of true infections throughout Africa (as they do in the U.S.), the contrast in cases is just as stark: 2,000 per million there, 56,000 per million here.
Read 7 tweets
25 Dec 20
From June, “Why Don’t Americans Trust Public-Health Experts?” (1/x) nymag.com/intelligencer/…
“In January, as the earliest scary research into the outbreak in Wuhan began arriving from China, public-health officials downplayed the threat and systematically advised coronavirus panic be channeled into vigilance about the flu, which they considered a bigger problem.” (2/x)
“In February, as initial data arrived from China showing a dramatic age skew in mortality, with the old at far greater risk, and the very old at greater risk still, political leaders and public-health officials did practically nothing to protect the most vulnerable.” (3/x)
Read 9 tweets
18 Dec 20
“For all the euphoria that rightly greeted Chinese President Xi Jinping’s announcement in September of a peak in carbon emissions by 2030 and a decline to net zero by 2060, the promise of that declaration is at risk,” ⁦@davidfickling⁩ writes (1/x). bloomberg.com/opinion/articl…
“To see why, consider Xi’s follow-up speech to the international Climate Ambition Summit on Dec. 12. While reiterating his earlier promises, it fell short on the most important point: How much China is prepared to spend decarbonizing its power system.”
“The installed capacity of solar and wind power will rise to at least 1,200 gigawatts by 2030, he said, compared to 440GW at present. That represents pedestrian growth of around 76GW a year, roughly in line with installations during 2018.”
Read 10 tweets
7 Dec 20
The most promising of the vaccines was fully designed before the first confirmed American case and was manufactured for testing before the first American death. How much faster could we have moved to deliver it? How many lives might've been saved? (1/x) nymag.com/intelligencer/…
"To start, this is—as the country and the world are rightly celebrating—the fastest timeline of development in the history of vaccines. It also means that for the entire span of the pandemic, which has killed more than 250,000 Americans, we had the tools we needed to prevent it."
"That a vaccine was available for the entire brutal duration may be, to future generations trying to draw lessons from our death and suffering, the most tragic, and ironic, feature of this plague."
Read 27 tweets

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