Six feet distancing not enough to stop coronavirus transmission in light winds: Study

News Network
May 20, 2020

London, May 20: The current physical distancing guidelines of 6 feet may be insufficient to prevent COVID-19 transmission, according to a study which says a mild cough in low wind speeds can propel saliva droplets by as much as 18 feet.

Researchers, including those from the University of Nicosia in Cyprus, said a good baseline for studying the airborne transmission of viruses, like the one behind the COVID-19 pandemic, is a deeper understanding of how particles travel through the air when people cough.

In the study, published in the journal Physics of Fluids, they said even with a slight breeze of about four kilometres per hour (kph), saliva travels 18 feet in 5 seconds.

"The droplet cloud will affect both adults and children of different heights," said study co-author Dimitris Drikakis from the University of Nicosia.

According to the scientists, shorter adults and children could be at higher risk if they are located within the trajectory of the saliva droplets.

They said saliva is a complex fluid, which travels suspended in a bulk of surrounding air released by a cough, adding that many factors affect how saliva droplets travel in the air.

These factors, the study noted, include the size and number of droplets, how they interact with one another and the surrounding air as they disperse and evaporate, how heat and mass are transferred, and the humidity and temperature of the surrounding air.

In the study, the scientists created a computer simulation to examine the state of every saliva droplet moving through the air in front of a coughing person.

The model considered the effects of humidity, dispersion force, interactions of molecules of saliva and air, and how the droplets change from liquid to vapour and evaporate, along with a grid representing the space in front of a coughing person.

Each grid, the scientists said, holds information about variables like pressure, fluid velocity, temperature, droplet mass, and droplet position.

The study analysed the fates of nearly 1,008 simulated saliva droplets, and solved as many as 3.7 million equations.

"The purpose of the mathematical modelling and simulation is to take into account all the real coupling or interaction mechanisms that may take place between the main bulk fluid flow and the saliva droplets, and between the saliva droplets themselves," explained Talib Dbouk, another co-author of the study.

However, the researchers added that further studies are needed to determine the effect of ground surface temperature on the behaviour of saliva in air.

They also believe that indoor environments, especially ones with air conditioning, may significantly affect the particle movement through air.

This work is important since it concerns safety distance guidelines, and advances the understanding of the transmission of airborne diseases, Drikakis said.

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Agencies
August 7,2020

Russia boasts that it's about to become the first country to approve a Covid-19 vaccine, with mass vaccinations planned as early as October using shots that are yet to complete clinical trials -- and scientists worldwide are sounding the alarm that the headlong rush could backfire.

Moscow sees a Sputnik-like propaganda victory, recalling the Soviet Union's launch of the world's first satellite in 1957.

But the experimental Covid-19 shots began first-in-human testing on a few dozen people less than two months ago, and there's no published scientific evidence yet backing Russia's late entry to the global vaccine race, much less explaining why it should be considered a front-runner.

“I'm worried that Russia is cutting corners so that the vaccine that will come out may be not just ineffective, but also unsafe,” said Lawrence Gostin, a global public health law expert at Georgetown University. “It doesn't work that way... Trials come first. That's really important.”

According to Kirill Dmitriev, head of Russia's Direct Investment Fund that bankrolled the effort, a vaccine developed by the Gamaleya research institute in Moscow may be approved in days, before scientists complete what's called a Phase 3 study.

That final-stage study, usually involving tens of thousands of people, is the only way to prove if an experimental vaccine is safe and really works.

Health Minister Mikhail Murashko said members of “risk groups,” such as medical workers, may be offered the vaccine this month.

He didn't clarify whether they would be part of the Phase 3 study that is said to be completed after the vaccine receives “conditional approval.”

Deputy Prime Minister Tatyana Golikova promised to start “industrial production” in September, and Murashko said mass vaccination may begin as early as October.

Dr Anthony Fauci, the top US infectious disease specialist, questioned the fast-track approach last week.

“I do hope that the Chinese and the Russians are actually testing a vaccine before they are administering the vaccine to anyone, because claims of having a vaccine ready to distribute before you do testing I think is problematic at best," he said.

Questions about this vaccine candidate come after the US, Britain and Canada last month accused Russia of using hackers to steal vaccine research from Western labs.

Delivering a vaccine first is a matter of national prestige for the Kremlin as it tries to assert the image of Russia as a global power capable of competing with the US and China.

The notion of being “the first in the world” dominated state news coverage of the effort, with government officials praising reports of the first-step testing.

In April, President Vladimir Putin ordered state officials to shorten the time of clinical trials for a variety of drugs, including potential coronavirus vaccines.

According to Russia's Association of Clinical Trials Organizations, the order set “an unattainable bar” for scientists who, as a result, "joined in on the mad race, hoping to please those at power.”

The association first raised concern in late May, when professor Alexander Gintsburg, head of the Gamaleya institute, said he and other researchers tried the vaccine on themselves.

The move was a “crude violation of the very foundations of clinical research, Russian law and universally accepted international regulations" the group said in an open letter to the government, urging scientists and health officials to adhere to clinical research standards.

But a month later, the Health Ministry authorized clinical trials of the Gamaleya product, with what appeared to be another ethical issue.

Human studies started June 17 among 76 volunteers. Half were injected with a vaccine in liquid form and the other half with a vaccine that came as soluble powder.

Some in the first half were recruited from the military, which raised concerns that servicemen may have been pressured to participate.

Some experts said their desire to perform well would affect the findings. “It's no coincidence media reports we see about the trials among the military said no one had any side effects, while the (other group) reported some," said Vasily Vlassov, a public health expert with Moscow's Higher School of Economics.

As the trials were declared completed and looming regulatory approval was announced last week, questions arose about the vaccine's safety and effectiveness.

Government assurances the drug produced the desired immune response and caused no significant side effects were hardly convincing without published scientific data describing the findings.

The World Health Organization said all vaccine candidates should go through full stages of testing before being rolled out.

“There are established practices and there are guidelines out,” WHO spokesman Christian Lindmeier said Tuesday.

“Between finding or having a clue of maybe having a vaccine that works, and having gone through all the stages, is a big difference.”

Offering an unsafe compound to medical workers on the front lines of the outbreak could make things worse, Georgetown's Gostin said, adding: “What if the vaccine started killing them or making them very ill?”

Vaccines that are not properly tested can cause harm in many ways — from a negative impact on health to creating a false sense of security or undermining trust in vaccinations, said Thomas Bollyky, director of the global health program at the Council on Foreign Relations. 

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Agencies
August 7,2020

New Delhi, Aug 7: India's COVID-19 cases tally crossed 20 lakh mark with the highest single-day spike of 62,538 cases on Friday, said Union Ministry of Health and Family Welfare.

The COVID-19 tally rises to 20,27,075 including 6,07,384 active cases, 13,78,106 cured/discharged/migrated and 41,585 deaths, according to the Ministry of Health.

Maharashtra with 1,46,268 active cases and 3,05,521 cured and discharged patients continues to be the worst affected. The state has also reported 16,476 deaths due to the infection.

Tamil Nadu has 54,184 active cases while 2,14,815 patients have been discharged after treatment in the state. 4,461 deaths have been reported due to COVID-19 in the state.

Andhra Pradesh with 80,426 active cases is the third on the list. There are 1,04,354 cured and discharged patients and 1,681 deaths reported from the state.

Delhi now has 10,072 active cases and 1,26,116 cured and discharged patients. 4,044 people have lost their lives due to the disease in the Union Territory so far. 

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News Network
March 19,2020

Rome, Mar 19: Italy on Wednesday reported 475 new deaths from the novel coronavirus, the highest one-day official toll of any nation since the first case was detected in China late last year.

The total number of deaths in Italy has reached 2,978, more than half of all the cases recorded outside China, while the number of infections stood at 35,713.

The previous record high of 368 deaths was also recorded in Italy, on Sunday. The nation of 60 million has now recorded 34.2 percent of all the deaths officially attributed to COVID-19 across the world.

With the death rate still climbing despite the Mediterranean country entering a second week under an effective lockdown, officials urged Italians to have faith and to stay strong.

"They main thing is, do not give up," Italian National Institute of Health chief Silvio Brusaferro said in a nationally televised press conference.

"It will take a few days before we see the benefits" of containment measures, said Brusaferro. "We must maintain these measures to see their effect, and above all to protect the most vulnerable."

Imposed nationally on March 12, the shutdown of most Italian businesses and a ban on public gatherings are due to expire on March 25.

But school closures and other measures, such as a ban fan attendance at sporting events, are due to run on until April 3.

A top government minister hinted Wednesday that the school closure would be extended well into next month, if not longer.

The rates within Italy itself remained stable, with two-thirds of the deaths -- 1,959 in all -- reported in the northern Lombardy region around Milan, the Italian financial and fashion capital.

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