40% Of People Have No Symptoms, They May Be Key To Ending Covid: Report

Agencies
August 9, 2020

When researcher Monica Gandhi began digging deeper into outbreaks of the novel coronavirus, she was struck by the extraordinarily high number of infected people who had no symptoms.

A Boston homeless shelter had 147 infected residents, but 88% had no symptoms even though they shared their living space. A Tyson Foods poultry plant in Springdale, Ark., had 481 infections, and 95% were asymptomatic.

Prisons in Arkansas, North Carolina, Ohio and Virginia counted 3,277 infected people, but 96% were asymptomatic.

During its seven-month global rampage, the coronavirus has claimed more than 700,000 lives. But Gandhi began to think the bigger mystery might be why it has left so many more practically unscathed.

What was it about these asymptomatic people, who lived or worked so closely to others who fell severely ill, she wondered, that protected them? Did the "dose" of their viral exposure make a difference? Was it genetics? Or might some people already have partial resistance to the virus, contrary to our initial understanding?

Efforts to understand the diversity in the illness are finally beginning to yield results, raising hope that the knowledge will help accelerate development of vaccines and therapies - or possibly even create new pathways toward herd immunity in which enough of the population develops a mild version of the virus that they block further spread and the pandemic ends.

"A high rate of asymptomatic infection is a good thing," said Gandhi, an infectious-disease specialist at the University of California at San Francisco. "It's a good thing for the individual and a good thing for society."

The coronavirus has left numerous clues - the uneven transmission in different parts of the world, the mostly mild impact on children. Perhaps most tantalizing is the unusually large proportion of infected people with mild symptoms or none at all. The Centers for Disease Control and Prevention last month estimated that rate at about 40%.

Those clues have sent scientists off in different directions: Some are looking into the role of the receptor cells, which the virus uses to infiltrate the body, to better understand the role that age and genetics might play. Others are delving into masks and whether they may filter just enough of the virus so those wearing them had mild cases or no symptoms at all.

The theory that has generated the most excitement in recent weeks is that some people walking among us might already have partial immunity.

When SARS-CoV-2, the technical name of the coronavirus that causes the disease covid-19, was first identified on Dec. 31, 2019, public health officials deemed it a "novel" virus because it was the first time it had been seen in humans who presumably had no immunity from it whatsoever. There's now some very early, tentative evidence suggesting that assumption might have been wrong.

One mind-blowing hypothesis - bolstered by a flurry of recent studies - is that a segment of the world's population may have partial protection thanks to "memory" T cells, the part of our immune system trained to recognize specific invaders. 

This could originate from cross-protection derived from standard childhood vaccinations. Or, as a paper published Tuesday in Science suggested, it could trace back to previous encounters with other coronaviruses, such as those that cause the common cold.

"This might potentially explain why some people seem to fend off the virus and may be less susceptible to becoming severely ill," National Institutes of Health Director Francis Collins remarked in a blog post this past week.

On a population level, such findings, if validated, could be far-reaching.

Hans-Gustaf Ljunggren, a researcher at Sweden's Karolinska Institute, and others have suggested that public immunity to the coronavirus could be significantly higher than what has been suggested by studies. In communities in Barcelona, Boston, Wuhan and other major cities, the proportion of people estimated to have antibodies and therefore presumably be immune has mostly been in the single digits. But if others had partial protection from T cells, that would raise a community's immunity level much higher.

This, Ljunggren said, would be "very good news from a public health perspective."

Some experts have gone so far as to speculate about whether some surprising recent trends in the epidemiology of the coronavirus - the drop in infection rates in Sweden where there have been no widespread lockdowns or mask requirements, or the high rates of infection in Mumbai's poor areas but little serious disease - might be due to preexisting immunity.

Others say it's far too early to draw such conclusions. Anthony Fauci, the United States' top infectious-disease expert, said in an interview that while these ideas are being intensely studied, such theories are premature. He said at least some partial preexisting immunity in some individuals seems a possibility.

And he said the amount of virus someone is exposed to - called the inoculum - "is almost certainly an important and likely factor" based on what we know about other viruses.

But Fauci cautioned that there are multiple likely reasons - including youth and general health - that determine whether a particular individual shrugs off the disease or dies of it. That reinforces the need, in his view, for continued vigilance in social distancing, masking and other precautions.

"There are so many other unknown factors that maybe determine why someone gets an asymptomatic infection," Fauci said. "It's a very difficult problem to pinpoint one thing."

- - -

News headlines have touted the idea based on blood tests that 20% of some New York communities might be immune, 7.3% in Stockholm, 7.1% in Barcelona. Those numbers come from looking at antibodies in people's blood that typically develop after they are exposed to a virus. But scientists believe another part of our immune system - T cells, a type of white blood cell that orchestrates the entire immune system - could be even more important in fighting against the coronavirus.

Recent studies have suggested that antibodies from the coronavirus seem to stick around for two to three months in some people. While work on T cells and the coronavirus is only getting started - testing T cells is much more laborious than antibody testing - previous research has shown that, in general, T cells tend to last years longer.

One of the first peer-reviewed studies on the coronavirus and T cells was published in mid-May in the journal Cell by Alessandro Sette, Shane Crotty and others at the La Jolla Institute for Immunology near San Diego.

The group was researching blood from people who were recovering from coronavirus infections and wanted to compare that to samples from uninfected controls who were donors to a blood bank from 2015 to 2018. The researchers were floored to find that in 40% to 60% of the old samples, the T cells seemed to recognize SARS-CoV-2.

"The virus didn't even exist back then, so to have this immune response was remarkable," Sette said.

Research teams from five other locations reported similar findings. In a study from the Netherlands, T cells reacted to the virus in 20% of the samples. In Germany, 34%. In Singapore, 50%.

The different teams hypothesized this could be due to previous exposure to similar pathogens. Perhaps fortuitously, SARS-CoV-2 is part of a large family of viruses. Two of them - SARS and MERS - are deadly and led to relatively brief and contained outbreaks. Four other coronavirus variants, which cause the common cold, circulate widely each year but typically result in only mild symptoms. Sette calls them the "less-evil cousins of SARS-CoV-2."

This week, Sette and others from the team reported new research in Science providing evidence the T cell responses may derive in part from memory of "common cold" coronaviruses.

"The immune system is basically a memory machine," he said. "It remembers and fights back stronger."

The researchers noted in their paper that the strongest reaction they saw was against the spike proteins that the virus uses to gain access to cells - suggesting that fewer viral copies get past these defenses.

"The current model assumes you are either protected or you are not - that it's a yes or no thing," Sette added. "But if some people have some level of preexisting immunity, that may suggest it's not a switch but more continuous."

- - -

More than 2,300 miles away, at the Mayo Clinic in Cleveland, Andrew Badley was zeroing in the possible protective effects of vaccines.

Teaming up with data experts from Nference, a company that manages their clinical data, he and other scientists looked at records from 137,037 patients treated at the health system to look for relationships between vaccinations and coronavirus infection.

They knew that the vaccine for smallpox, for example, had been shown to protect against measles and whooping cough. Today, a number of existing vaccines are being studied to see whether any might offer cross-protection against SARS-CoV-2.

When SARS-CoV-2, the technical name of the coronavirus that causes the disease covid-19, was first identified on Dec. 31, 2019

The results were intriguing: Seven types of vaccines given one, two or five years in the past were associated with having a lower rate of infection with the new coronavirus. Two vaccines in particular seemed to show stronger links: People who got a pneumonia vaccine in the recent past appeared to have a 28% reduction in coronavirus risk. Those who got polio vaccines had a 43% reduction in risk.

Venky Soundararajan, chief scientific officer of Nference, remembers when he first saw how large the reduction appeared to be, he immediately picked up his phone and called Badley: "I said, 'Is this even possible?'"

The team looked at dozens of other possible explanations for the difference. It adjusted for geographic incidence of the coronavirus, demographics, comorbidities, even whether people had had mammograms or colonoscopies, under the assumption that people who got preventive care might be more apt to social distance. But the risk reduction still remained large.

"This surprised us completely," Soundararajan recalled. "Going in we didn't expect anything or maybe one or two vaccines showing modest levels of protection."

The study is only observational and cannot show a causal link by design, but Mayo researchers are looking at a way to quantify the activity of these vaccines on the coronavirus to serve as a benchmark to the new vaccines being created by companies such as Moderna. If existing vaccines appear as protective as new ones under development, he said, they could change the world's whole vaccine strategy.

- - -

Meanwhile, at NIH headquarters in Bethesda, Md., Alkis Togias has been laser-focused on one group of the mildly affected: children. He wondered whether it might have something to do with the receptor known as ACE2, through which the virus hitchhikes into the body.

In healthy people, the ACE2 receptors perform the important function of keeping blood pressure stable. The novel coronavirus latches itself to ACE2, where it replicates. Pharmaceutical companies are trying to figure out how to minimize the receptors or to trick the virus into attaching itself to a drug so it does not replicate and travel throughout the body.

Was it possible, Togias asked, that children naturally expressed the receptor in a way that makes them less vulnerable to infection?

He said recent papers have produced counterintuitive findings about one subgroup of children - those with a lot of allergies and asthma. The ACE2 receptors in those children were diminished, and when they were exposed to an allergen such as cat hair, the receptors were further reduced. Those findings, combined with data from hospitals showing that asthma did not seem to be a risk factor for the respiratory virus, as expected, have intrigued researchers.

"We are thinking allergic reactions may protect you by down-regulating the receptor," he said. "It's only a theory of course."

Togias, who is in charge of airway biology for the National Institute of Allergy and Infectious Diseases, is looking at how those receptors seem to be expressed differently as people age, as part of a study of 2,000 U.S. families. By comparing those differences and immune responses within families, they hope to be able to better understand the receptors' role.

Separately, a number of genetic studies show variations in genes associated with ACE2 with people from certain geographic areas, such as Italy and parts of Asia, having distinct mutations. No one knows what significance, if any, these differences have on infection, but it's an active area of discussion in the scientific community.

- - -

Before the pandemic, Gandhi, the University of California researcher, specialized in HIV. But like other infectious-disease experts these days, she has spent many of her waking hours thinking about the coronavirus. And in scrutinizing the data on outbreaks one day, she noticed what might be a pattern: People were wearing masks in the settings with the highest percentage of asymptomatic cases.

The numbers on two cruise ships were especially striking. In the Diamond Princess, where masks weren't used and the virus was likely to have roamed free, 47% of those tested were asymptomatic. But in the Antarctic-bound Argentine cruise ship, where an outbreak hit in mid-March and surgical masks were given to all passengers and N95 masks to the crew, 81% were asymptomatic.

Similarly high rates of asymptomatic infection were documented at a pediatric dialysis unit in Indiana, a seafood plant in Oregon and a hair salon in Missouri, all of which used masks. Gandhi was also intrigued by countries such as Singapore, Vietnam and the Czech Republic that had population-level masking.

"They got cases," she noted, "but fewer deaths."

The scientific literature on viral dose goes back to around 1938 when scientists began to find evidence that being exposed to one copy of a virus is more easily overcome than being exposed to a billion copies. Researchers refer to the infectious dose as ID50 - or the dose at which 50% of the population would become infected.

While scientists do not know what that level might be for the coronavirus (it would be unethical to expose humans in this way), previous work on other nonlethal viruses showed that people tend to get less sick with lower doses and more sick with higher doses. A study published in late May involving hamsters, masks and SARS-CoV-2 found that those given coverings had milder cases than those who did not get them.

In an article published this month in the Journal of General Internal Medicine, Gandhi noted that in some outbreaks early in the pandemic in which most people did not wear masks, 15% of the infected were asymptomatic. But later on, when people began wearing masks, the rate of asymptomatic people was 40% to 45%.

She said the evidence points to masks not just protecting others - as U.S. health officials emphasize - but protecting the wearer as well. Gandhi makes the controversial argument that while people mostly have talked about asymptomatic infections as terrifying due to how people can spread the virus unwittingly, it could end up being a good thing.

"It is an intriguing hypothesis that asymptomatic infection triggering immunity may lead us to get more population-level immunity," Gandhi said. "That itself will limit spread."

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coastaldigest.com web desk
June 27,2020

New Delhi, June 27: The Prime Minister Narendra Modi-led union government of India is not ready to stop all imports from aggressive China in spite of mount calls to boycott Chinese products in India.

The Centre is reportedly considering to stop only non-essential imports from the neighbouring country.

However, the Inward shipment in sectors such as automobiles, pharmaceuticals, certain electronics and others will continue until a domestic alternative is found.

“India will gradually move towards import substitution. It will not happen overnight. In the meantime, attention has to be paid on production and job creation. We cannot throttle our industry. There are certain absolutely essential imports. Needless to say, those will keep going,” official sources said.

Sources said that both the government and the industry are in the process of identifying products that can be domestically manufactured in the medium term. There are certain chemicals, automotive components, handicrafts, cosmetics, agriculture items and certain consumer electronics, which can be manufactured domestically in the short to medium term. The government is doing all it can to raise the capacity of domestic industries.

However, there are certain other imports in the automobile and the pharmaceutical sectors which cannot be done away within the short to medium term. Their domestic production at the moment may not be that cost-effective.

The six-crore strong traders’ body CAIT has been at the forefront of such a demand and has launched a campaign to celebrate Indian Diwali this year with a total absence of Chinese goods.

“Ease of doing business, capital availability at lower rates and globally competitive logistics and energy costs are some of the prerequisites that the government should look into to ensure the growth of the domestic auto component industry,” according to Automotive Component Manufacturers Association of India (ACMA) Director General Vinnie Mehta.

Maruti Suzuki Chairman R C Bhargava said, “People who are boycotting Chinese goods have to remember that in some cases it may lead to their being asked to pay more for the same product."

Meanwhile, domestic rating agency Acuite Ratings & Research has analysed the current import portfolio from China and found 40 sub-sectors have the potential to lower their import dependency on China. These sectors contribute to $33.6 billion worth of imports from China and about 25% of these imports can be substituted by local manufacturing without any significant additional investments.

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Agencies
February 29,2020

Doha, Feb 29: The United States signed a landmark deal with the Taliban on Saturday, laying out a timetable for a full troop withdrawal from Afghanistan within 14 months as it seeks an exit from its longest-ever war.

President Donald Trump urged the Afghan people to embrace the chance for a new future, saying the deal held out the possibility of ending the 18-year conflict.

"If the Taliban and the government of Afghanistan live up to these commitments, we will have a powerful path forward to end the war in Afghanistan and bring our troops home," he said on the eve of the event in Doha.

Secretary of State Mike Pompeo arrived in the Qatari capital to witness the signing of the accord, while Defence Secretary Mark Esper was in Kabul for a separate joint declaration with the Afghan government.

The agreement is expected to lead to a dialogue between the Kabul government and the Taliban that, if successful, could ultimately see the Afghan war wind down.

But the position of the Afghan government, which has been excluded from direct US-Taliban talks, remains unclear and the country is gripped by a fresh political crisis amid contested election results.

The United States and its allies will withdraw all their forces from Afghanistan within 14 months if the Taliban abide by the Doha agreement, Washington and Kabul said in a joint statement.

After an initial reduction of troops to 8,600 within 135 days of Saturday's signing, the US and its partners "will complete the withdrawal of their remaining forces from Afghanistan within 14 months... and will withdraw all their forces from remaining bases", the declaration stated.

The Doha accord was drafted over a tempestuous year of dialogue marked by the abrupt cancellation of the effort by Trump in September.

The signing comes after a week-long, partial truce that has mostly held across Afghanistan, aimed at building confidence between the warring parties and showing the Taliban can control their forces.

NATO Secretary General Jens Stoltenberg heralded the agreement as a "first step to lasting peace".

"The way to peace is long and hard. We have to be prepared for setbacks, spoilers, there is no easy way to peace but this is an important first step," the Norwegian former prime minister told reporters in Kabul.

Since the US-led invasion that ousted the Taliban after the September 11, 2001 attacks, America has spent more than $1 trillion in fighting and rebuilding in Afghanistan.

About 2,400 US soldiers have been killed, along with unknown tens of thousands of Afghan troops, Taliban fighters and Afghan civilians.

The insurgents said they had halted all hostilities Saturday in honour of the agreement.

"Since the deal is being signed today, and our people are happy and celebrating it, we have halted all our military operations across the country," Taliban spokesman Zabihullah Mujahid told AFP.

Close to 30 nations were represented at Saturday's signing in the Qatari capital.

While Kabul will not be represented at the Doha ceremony, set for 1245 GMT, it will send a six-person taskforce to the Qatari capital to make initial contact with the Taliban political office, established in 2013.

Any insurgent pledge to guarantee Afghanistan is never again used by jihadist movements such as Al-Qaeda and the Islamic State group to plot attacks abroad will be key to the deal's viability.

The Taliban's sheltering of Al-Qaeda was the main reason for the US invasion following the 9/11 attacks.

The group, which had risen to power in the 1990s in the chaos of civil war, suffered a swift defeat at the hands of the US and its allies. They retreated before re-emerging to lead a deadly insurgency against the new government in Kabul.

After the NATO combat mission ended in December 2014, the bulk of Western forces withdrew from the country, leaving it in an increasingly precarious position.

While Afghans are eager to see an end to the violence, experts say any prospective peace will depend on the outcome of talks between the Taliban and the Kabul government.

But with President Ashraf Ghani and rival Abdullah Abdullah at loggerheads over contested election results, few expect the pair to present a united front, unlike the Taliban, who would then be in a position to take the upper hand in negotiations.

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News Network
January 20,2020

Davos, Jan 20: India's richest 1 per cent hold more than four-times the wealth held by 953 million people who make up for the bottom 70 per cent of the country's population, while the total wealth of all Indian billionaires is more than the full-year budget, a new study said on Monday.

Releasing the study 'Time to Care' here ahead of the 50th annual meeting of the World Economic Forum (WEF), rights group Oxfam also said the world's 2,153 billionaires have more wealth than the 4.6 billion people who make up 60 per cent of the planet's population.

The report flagged that global inequality is shockingly entrenched and vast and the number of billionaires has doubled in the last decade, despite their combined wealth having declined in the last year.

"The gap between rich and poor can't be resolved without deliberate inequality-busting policies, and too few governments are committed to these," said Oxfam India CEO Amitabh Behar, who is here to represent the Oxfam confederation this year.

The issues of income and gender inequality are expected to figure prominently in discussions at the five-day summit of the WEF, starting Monday. The WEF's annual global risks Report has also warned that the downward pressure on the global economy from macroeconomic fragilities and financial inequality continued to intensify in 2019.

Concern about inequality underlies recent social unrest in almost every continent, although it may be sparked by different tipping points such as corruption, constitutional breaches, or the rise in prices for basic goods and services, as per the WEF report.

Although global inequality has declined over the past three decades, domestic income inequality has risen in many countries, particularly in advanced economies and reached historic highs in some, the Global Risks Report flagged last week.

The Oxfam report further said "sexist" economies are fuelling the inequality crisis by enabling a wealthy elite to accumulate vast fortunes at the expense of ordinary people and particularly poor women and girls.

Regarding India, Oxfam said the combined total wealth of 63 Indian billionaires is higher than the total Union Budget of India for the fiscal year 2018-19 which was at Rs 24,42,200 crore.

"Our broken economies are lining the pockets of billionaires and big business at the expense of ordinary men and women. No wonder people are starting to question whether billionaires should even exist," Behar said.

As per the report, it would take a female domestic worker 22,277 years to earn what a top CEO of a technology company makes in one year.

With earnings pegged at Rs 106 per second, a tech CEO would make more in 10 minutes than what a domestic worker would make in one year.

It further said women and girls put in 3.26 billion hours of unpaid care work each and every day -- a contribution to the Indian economy of at least Rs 19 lakh crore a year, which is 20 times the entire education budget of India in 2019 (Rs 93,000 crore).

Besides, direct public investments in the care economy of 2 per cent of GDP would potentially create 11 million new jobs and make up for the 11 million jobs lost in 2018, the report said.

Behar said the gap between rich and poor cannot be resolved without deliberate inequality-busting policies, and too few governments are committed to these.

He said women and girls are among those who benefit the least from today's economic system.

"They spend billions of hours cooking, cleaning and caring for children and the elderly. Unpaid care work is the 'hidden engine' that keeps the wheels of our economies, businesses and societies moving.

"It is driven by women who often have little time to get an education, earn a decent living or have a say in how our societies are run, and who are therefore trapped at the bottom of the economy,” Behar added.

Oxfam said governments are massively under-taxing the wealthiest individuals and corporations and failing to collect revenues that could help lift the responsibility of care from women and tackle poverty and inequality.

Besides, the governments are also underfunding vital public services and infrastructure that could help reduce women and girls' workload, the report said.

As per the global survey, the 22 richest men in the world have more wealth than all the women in Africa.

Besides, women and girls put in 12.5 billion hours of unpaid care work each and every day -- a contribution to the global economy of at least USD 10.8 trillion a year, more than three times the size of the global tech industry.

Getting the richest one per cent to pay just 0.5 per cent extra tax on their wealth over the next 10 years would equal the investment needed to create 117 million jobs in sectors such as elderly and childcare, education and health.

Governments must prioritise care as being as important as all other sectors in order to build more human economies that work for everyone, not just a fortunate few, Behar said.

Oxfam said its calculations are based on the latest data sources available, including from the Credit Suisse Research Institute's Global Wealth Databook 2019 and Forbes' 2019 billionaires list.

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