‘According to a “potentially revolutionary” theory put forward by Professor Ituro Inoue, a genetics expert, the Delta variant simply accumulated too many mutations to the virus’s error-correcting protein called nsp14. Prof Inoue says the virus struggled to repair the errors in time and ultimately caused its own “self-destruction”.
Read here (News.com.au, Nov 22, 2021)
‘Pregnant women who tested positive for Covid-19 when admitted to a hospital to give birth were at a greater risk for stillbirth compared to those who did not, according to a study released by the U.S. Centers for Disease Control on Friday, with risks rising more since the delta variant has become the dominant strain.’
Read here (Forbes, Nov 19, 2021)
Read CDC report here.
“Breakthrough cases,” where people who are fully vaccinated get COVID-19, are still considered rare, even with Delta, according to the CDC, but if a vaccinated person is infected, they can transmit the virus. (The CDC is continuing to assess data on whether people with breakthrough cases who don’t have symptoms can spread the virus.) Here are five things you need to know about the Delta variant.
Read here (Yale Medicine, Sept 8, 2021)
‘As the rollout of COVID-19 vaccines continues, public attention is increasingly turning to booster shots, which aim to top up immunity if it wanes. But is a third dose needed? And if so, when? Let’s take a look at what the data tell us so far about how long immunity from COVID-19 vaccines might last.
Read here (The Conversation, Aug 30, 2021)
‘In the worst-case scenario, a variant could arise that would “make it like the vaccines did not exist,” Hanage [Bill Hanage, an epidemiologist at the Harvard School of Public Health] said. But at the moment, “there is no such variant like that.” And it would probably be extraordinarily difficult for one to manifest. Even the most evasive variants we know of—the ones that have stumped certain antibodies—aren’t fully duping vaccinated bodies, which harbor a slew of other immunological guards. Hanage also pointed out that many people’s immune systems have been trained on different triggers—distinct brands of vaccines, unique variants, or some combination thereof. A new version of SARS-CoV-2 would find skirting all of those blockades at once to be nearly impossible.
‘Viruses aren’t infinitely mutable; sometimes, to keep themselves in contention, they must make sacrifices. Several experts told me they’re hopeful that the coronavirus might struggle to max out both transmission and immune evasion at once, requiring some sort of trade-off between the two. Some of the most powerful anti-coronavirus antibodies target SARS-CoV-2’s spike protein, which the virus uses to unlock and enter our cells. If the virus altered the protein to sidestep those antibodies, it might make itself less recognizable to the immune system. But it could also hurt its ability to infect us at all.’
Read here (The Atlantic, Aug 25, 2021)
‘This article updates our perspectives on when the coronavirus pandemic will end to reflect the latest information on vaccine rollout, variants of concern, and disease progression. Among high-income countries, cases caused by the Delta variant reversed the transition toward normalcy first in the United Kingdom, during June and July of 2021, and subsequently in the United States and elsewhere. Our own analysis supports the view of others that the Delta variant has effectively moved overall herd immunity out of reach in most countries for the time being. The United Kingdom’s experience nevertheless suggests that once a country has weathered a wave of Delta-driven cases, it may be able to resume the transition toward normalcy. Beyond that, a more realistic epidemiological endpoint might arrive not when herd immunity is achieved but when COVID-19 can be managed as an endemic disease. The biggest overall risk would likely then be the emergence of a significant new variant.’
Read here (McKinsey & Co, August 23, 2021)
‘Israel was the first country on Earth to fully vaccinate a majority of its citizens against COVID-19. Now it has one of the world's highest daily infection rates — an average of nearly 7,500 confirmed cases a day, double what it was two weeks ago. Nearly one in every 150 people in Israel today has the virus.
‘What happened, and what can be learned about the vaccine's impact on a highly vaccinated country? Here are six lessons learned — and one looming question for the future of the pandemic.’
Looming question: Will we need COVID-19 vaccines every several months? We don't know.
Read here (NPR, August 20, 2021)
‘Vaccination was a reprieve from this calculus of personal danger, at least for a while—get vaccinated, get your family and friends vaccinated, get back to a far more normal version of life. To a certain extent, that logic holds: The vaccines are still doing a fantastic job preventing hospitalization and death from the coronavirus’s far-more-transmissible Delta variant. But as COVID-19 cases and hospitalizations have roared back, concerns about breakthrough cases among the vaccinated and increased transmissibility among kids have muddied a lot of people’s ability to gauge their own day-to-day risk, just as they’d begun to venture back out into the world and hug, eat, and laugh in the same airspace together again. In some ways, pandemic life is more confusing than ever.’
Read here (The Atlantic, August 19, 2021)
‘We have all been occupied by the political situation in the country, but the Covid-19 virus is not. It is continuing its relentless march forward, whether we are focused on it or not. While an efficient government that deals with the pandemic decisively is crucial for the country, Malaysians need to be prepared for what is coming our way. I would like to share with you some possible scenarios for the coming weeks and months, and some thoughts and opinions based on current data.
Read here (Code Blue, August 19, 2021)
‘Pandemics end. But this one is not yet over, and especially not globally. Just 16 percent of the world’s population is fully vaccinated. Many countries, where barely 1 percent of people have received a single dose, are “in for a tough year of either lockdowns or catastrophic epidemics,” Adam Kucharski, the infectious-disease modeler, told me. The U.S. and the U.K. are further along the path to endemicity, “but they’re not there yet, and that last slog is often the toughest,” he added. “I have limited sympathy for people who are arguing over small measures in rich countries when we have uncontrolled epidemics in large parts of the world.”
‘Eventually, humanity will enter into a tenuous peace with the coronavirus. COVID-19 outbreaks will be rarer and smaller, but could still occur once enough immunologically naive babies are born. Adults might need boosters once immunity wanes substantially, but based on current data, that won’t happen for at least two years. And even then, “I have a lot of faith in the immune system,” Marion Pepper, the immunologist, said. “People may get colds, but we’ll have enough redundancies that we’ll still be largely protected against severe disease.” The bigger concern is that new variants might evolve that can escape our current immune defenses—an event that becomes more likely the more the coronavirus is allowed to spread. “That’s what keeps me up at night,” Georgetown’s Shweta Bansal told me.
‘To guard against that possibility, the world needs to stay alert. Regular testing of healthy people can tell us where the virus might be surging back.’
Read here (The Atlantic, August 12, 2021)
‘Delta is a deadly variant. It spreads like wildfire and kills efficiently. We need to be careful.
If you’re an individual
‘If you’re vaccinated, you’re mostly safe, especially with mRNA vaccines. Keep your guard up for now, avoid events that might become super-spreaders, but you don’t need to worry much more than that. If you’re not vaccinated though, this is a much more dangerous time than March 2020. The transmission rate is higher than it used to be, and if you catch Delta, you’re much more likely to die—or get Long COVID. You should be extra careful, only hang out with other vaccinated people, and avoid dangerous events.’
If you’re a community leader
‘If you’re in charge of a community, you have two goals:
‘However, if you have vaccinated everybody that wants to be vaccinated, and the rest simply doesn’t want to get vaccinated, then the calculation changes drastically. If your location values the freedom of its people to make the wrong decisions (as long as they don’t impact others), then you might consider opening up the economy. Delta will tear through those unvaccinated, but that’s their prerogative. Maybe the reality will hit better then.
‘But it really depends on each society. Opening up without full vaccination would infect some of those vaccinated, about 10% of them would get long COVID7, and about 0.3% of them would die8.
‘So here each society needs to decide. Say 40% don’t want to vaccinate. Is the freedom of 40% to not vaccinate worth the deaths and Long COVID of those vaccinated? Otherwise, are you willing to force people to vaccinate? Are you going to keep the country closed until there’s a booster vaccine? Will you be able to get your fences and test-trace-isolate programs to work?’
If you’re in charge of vaccine policy
‘An R0 of 8 is bad news for herd immunity. It puts its threshold at ~90% of people protected, which is impossible to reach if vaccines are only 65% protective of infection. Booster shots are necessary. Let’s accelerate their testing, approval, release, and deployment.
‘Also, support vaccine mix-and-match. In most countries, today, if you need a boost you are forced to take the same vaccine. But mixing types likely protects you better and is as safe as using the same type.’
If you’re in a developing country
‘We don’t pay enough attention to developing countries. Most of the science and media focuses where the money is, in developed economies. But Delta is very hard in developing countries, especially in dense urban areas where the poor are forced to work but live in close quarters with many others. India, Argentina, Tunisia, South Africa, and Indonesia are very sad examples of this.
‘Unfortunately, there’s not many special tricks that poor countries can pull. They tend to have a younger population, which helps. The one thing they have going on for them is that they tend to be warmer and more humid, which helps against COVID. Also, thanks to a warmer weather, they can have more events outdoors. This is the one thing they can leverage: have as many of your gatherings outside, while you do everything you can to vaccinate your population, and delay as much as you can the arrival of Delta with strong fences.
‘Let’s hope vaccine production keeps growing and people the world over can get vaccinated before the fall.’
Read here (Uncharted Waters, Aug 11, 2021)
‘You shared the last article about the Delta Variant so much that nearly 400,000 people read it. Thanks for spreading the word on something so important. You also asked so many good questions that I have tried to answer as many as I could in this article. It’s so long that I split it in two pieces. This 1st piece covers these questions:
Read here (Uncharted Territories, Aug 11, 2021)
Note: Part 2 is only premier, paid subscribers
‘Viral load is roughly 1,000 times higher in people infected with the Delta variant than those infected with the original coronavirus strain, according to a study in China...
‘The combination of a high number of viruses and a short incubation period makes sense as an explanation for Delta’s heightened transmissibility, says epidemiologist Benjamin Cowling at the University of Hong Kong. The sheer amount of virus in the respiratory tract means that superspreading events are likely to infect even more people, and that people might begin spreading the virus earlier after they become infected.
‘And the short incubation makes contact tracing more difficult in countries such as China, which systematically tracks each infected person’s contacts and require them to quarantine. “Putting it all together, Delta’s really difficult to stop,” Cowling says.’
Read here (Nature, July 21, 2021)