Watching too much TV may cause early death: Study.

Early treatment with the antiviral drug remdesivir has been found to reduce viral load and prevent lung disease in macaques infected with SARS-CoV-2 that causes COVID-19, according to a study.

The findings, published in the journal Nature on Tuesday, support the early use of remdesivir treatment in patients with COVID-19 to prevent progression to pneumonia.

Researchers from the National Institutes of Health in the US noted that remdesivir has broad antiviral activity and has been shown to be effective against infections with SARS-CoV and MERS-CoV in animal models.

The drug is being tested in human clinical trials for the treatment of COVID-19, they said.

Researcher Emmie de Wit and colleagues investigated the effects of remdesivir treatment in rhesus macaques, a recently established model of SARS-CoV-2 infection.

Two sets of six macaques were inoculated with SARS-CoV-2.

One group was treated with remdesivir 12 hours later -- close to the peak of virus reproduction in the lungs -- and these macaques received treatment every 24 hours until six days after inoculation.

In contrast to the control group, the researchers found that macaques that received remdesivir did not show signs of respiratory disease, and had reduced damage to the lungs.

Viral loads in the lower respiratory tract were also reduced in the treated animals; viral levels were around 100 times lower in the lower-respiratory tract of remdesivir-treated macaques 12 hours after the first dose, they said.

The researchers said that infectious virus could no longer be detected in the treatment group three days after initial infection, but was still detectable in four out of six control animals.

Despite this virus reduction in the lower respiratory tract, no reduction in virus shedding was observed, which indicates that clinical improvement may not equate to a lack of infectiousness, they said.

Dosing of remdesivir in the rhesus macaques is equivalent to that used in humans, the researchers noted.

They cautioned that it is difficult to directly translate the timing of treatment used in corresponding disease stages in humans, because rhesus macaques normally develop only mild disease.

However, researchers said the results indicate that remdesivir treatment of COVID-19 should be initiated as early as possible to achieve the maximum treatment effect.

Lower neighbourhood socioeconomic status and greater household crowding increase the risk of becoming infected with SARS-CoV-2, the virus that causes COVID-19, warn researchers.

"Our study shows that neighbourhood socioeconomic status and household crowding are strongly associated with risk of infection," said study lead author Alexander Melamed from Columbia University in the US.

"This may explain why Black and Hispanic people living in these neighbourhoods are disproportionately at risk for contracting the virus," Melamed added.

For the findings, published in the journal JAMA, the researchers examined the relationships between COVID-19 infection and neighbourhood characteristics in 396 women who gave birth during the peak of the Covid-19 outbreak in New York City. Since March 22, all women admitted to the hospitals for delivery have been tested for the virus, which gave the researchers the opportunity to detect all infections -- including infections with no symptoms -- in a defined population

The strongest predictor of COVID-19 infection among these women was residence in a neighbourhood where households with many people are common.The findings showed that women who lived in a neighbourhood with high household membership were three times more likely to be infected with the virus. Neighbourhood poverty also appeared to be a factor, the researchers said.Women were twice as likely to get COVID-19 if they lived in neighbourhoods with a high poverty rate, although that relationship was not statistically significant due to the small sample size.

The study revealed that there was no association between infection and population density.

"New York City has the highest population density of any city in the US, but our study found that the risks are related more to density in people's domestic environments rather than density in the city or within neighbourhoods," says co-author Cynthia Gyamfi-Bannerman."

The knowledge that SARS-CoV-2 infection rates are higher in disadvantaged neighbourhoods and among people who live in crowded households could help public health officials target preventive measures," the authors wrote.

Recently, another study published in the Journal of the American Planning Association, showed that dense areas were associated with lower COVID-19 death rates.

A team of scientists has produced first open source all-atom models of full-length COVID-19 Spike protein that facilitates viral entry into host cells – a discovery that can facilitate a faster vaccine and antiviral drug development.

The group from Seoul National University in South Korea, University of Cambridge in the UK and Lehigh University in the US produced the first open-source all-atom models of a full-length S protein.

The researchers say this is of particular importance because the S protein plays a central role in viral entry into cells, making it a main target for vaccine and antiviral drug development.

"Our models are the first full-length SARS-CoV-2 spike (S) protein models that are available to other scientists," said Wonpil Im, a professor in Lehigh University.

"Our team spent days and nights to build these models very carefully from the known cryo-EM structure portions. Modeling was very challenging because there were many regions where simple modeling failed to provide high-quality models," he wrote in a paper published in The Journal of Physical Chemistry B.

Scientists can use the models to conduct innovative and novel simulation research for the prevention and treatment of Covid-19.

Though the coronavirus uses many different proteins to replicate and invade cells, the Spike protein is the major surface protein that it uses to bind to a receptor.

The total number of global COVID-19 cases was nearing 9 million, while the deaths have increased to over 467,000, according to the Johns Hopkins University.

With 2,279,306 cases and 119,967 deaths, the US continues with the world's highest number of COVID-19 infections and fatalities, according to the CSSE.

Brazil comes in the second place with 1,083,341 infections and 50,591 deaths.