COVID-19: Record 4,591 Americans die in last 24 hours

Canadian researchers are developing a DNA vaccine for SARS-CoV-2, the coronavirus that causes COVID-19 and has currently infected nearly 5,00,000 people worldwide and crippled the global economy.

Entos Pharmaceuticals, a health-care biotechnology company headed by a University of Alberta researchers, develop new therapeutic compounds using the company's proprietary drug-delivery platform and has begun manufacturing vaccine candidates against the novel coronavirus.

"Given the urgency of the situation, we can have a lead candidate vaccine within two months. Once we have that it's a race to get it into clinical trials," said John Lewis, CEO of Entos and a Professor at the University of Alberta in Canada.

Lewis said in comparison to a traditional vaccine, DNA-based vaccines hold several advantages.

Nucleic acids are introduced directly into the patient's own cells, causing them to make pieces of the virus--tricking the immune system into mounting a response without the full virus actually being present, the researcher said.

According to the company, the approach is recognised as being easier to move into large-scale manufacturing, offers improved vaccine stability and works without needing an infectious agent.

In the current absence of a vaccine for COVID-19, several companies around the world are mounting efforts to begin similar work.

The first clinical trial using a DNA-based vaccine developed by Moderna Inc.in the US on March 13.

Their approach allows for antibodies to be made in the human trial volunteers against a specific protein on the surface of the coronavirus that lets the virus enter human cells.

The hope is that the antibodies will stop the interaction.

Though this approach is designed to be effective against COVID-19 specifically, Lewis said Entos is taking a different tack.

The company plans to use plasmid DNA to amplify the production of key coronavirus surface and structural proteins with each injection, with an eye to the bigger picture.

"Many of the structural proteins in the virus are pretty well conserved across all the coronaviruses, including SARS and MERS," said Lewis.

"We're hoping that if we express more of the structural proteins that are common to most coronaviruses, we can inhibit the current COVID-19, and also potentially protect against all coronaviruses both past and future," Lewis added.

To move the project forward quickly, the company is seeking financial support from both provincial and federal levels of government.

"We have the opportunity to save a lot of lives, and I think it's really upon us and governments to find solutions for that," Lewis said.

Washington, Jun 12: US President Donald Trump is considering suspending a number of employment visas including the H-1B, most sought-after among Indian IT professionals, in view of the massive unemployment in America due to the coronavirus pandemic, according to a media report.

The proposed suspension could extend into the government’s new fiscal year beginning October 1, when many new visas are issued, The Wall Street Journal reported on Thursday, quoting unnamed administration officials.

“That could bar any new H-1B holder outside the country from coming to work until the suspension is lifted, though visa holders already in the country are unlikely to be affected,” the daily reported.

H-1B is the most coveted foreign work visas for technology professionals from India.

Such a decision by the Trump administration is likely to have an adverse impact on thousands of Indian IT professionals. Already a large number of Indians on the H-1B visas have lost their jobs and are headed back home during the coronavirus pandemic.

The White House, however, said that no final decision has been made and the administration is considering various proposals.

“The administration is currently evaluating a wide range of options, formulated by career experts, to protect American workers and job seekers especially disadvantaged and underserved citizens — but no decisions of any kind have been made,” White House spokesman Hogan Gidley said in a statement.

In addition to the H-1B visas, the suspension could apply to the H-2B visa for short-term seasonal workers, the J-1 visa for short-term workers including camp counselors and au pairs and the L-1 visa for internal company transfers, the financial daily reported.

Meanwhile, the US Chambers of Commerce CEO Thomas Donohue on Thursday wrote a letter to Trump, expressing concern over his reported move on temporary work visas.

“As the economy rebounds, American businesses will need assurances that they can meet all their workforce needs. To that end, it is crucial that they have access to talent both domestically and from around the world,” Donohue wrote in a letter to Trump.

According to The Hill newspaper, Donohue said that American businesses need L-1 visa holders, who have a work visa valid for a relatively short amount of time, for necessary expertise.

He noted the importance of H-1B visa holders, who have a work visa valid for multiple years, for various industries, including technology, accounting and manufacturers, the newspaper said.

“Policies that would, for example, impose wide-ranging bans on the entry of nonimmigrant workers or impose burdensome new regulatory requirements on businesses that employ foreign nationals would undermine that access to talent and in the process, undercut our economy’s ability to grow and create jobs,” Donohue added.

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.