'Children under the age of 5 carry higher levels of Covid-19'

The Union health ministry on Friday revised the dosage of anti-viral drug remdesivir to be administered to coronavirus patients in the moderate stage of illness from the earlier six days to five days as it issued an updated 'Clinical Management Protocols for COVID-19'.

The drug, administered in the form of injection, should be given at a dose of 200 mg on day one followed by 100 mg daily for four days (total five days), the new treatment protocols stated.

The Health Ministry on June 13 had allowed the use of remdesivir for restricted emergency use in moderate cases under "investigational therapies".

"Under emergency use authorisation, remdesivir may be considered for patients in moderate stage requiring oxygen support," the document stated.

It is not recommended for those with severe renal impairment and high level of liver enzymes, pregnant and lactating women, and those below 12 years, it said.

The ministry also okayed off-label application of tocilizumab, a drug that modifies the immune system or its functioning, and convalescent plasma for treating COVID-19 patients in the moderate stage of illness as "investigational therapies".

It also recommended hydroxychloroquine for patients during the early course of the disease and not for critically-ill patients.

On June 27, the ministry had included an inexpensive, widely used steroid dexamethasone in treatment protocols for COVID-19 patients in the moderate to severe stages of their illness among other therapeutic measures.

The ministry advised use of dexamethasone, which is already used in a wide range of conditions for its anti-inflammatory and immunosuppressant effects, as an alternative choice to methylprednisolone for managing moderate to severe cases of coronavirus infection.

India's COVID-19 cases soared by over 20,000 in a day for the first time taking the country's total tally to 6,25,544 on Friday while the death toll climbed to 18,213 with 379 new fatalities, according to the Union Health Ministry data updated at 8 am.

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.

The World Health Organisation (WHO) Director-General Tedros Adhanom Ghebreyesus said that more research needs to be done to better understand the extent to which COVID-19 is being spread by people who don't show symptoms.

"Since early February, we have said that asymptomatic people can transmit COVID-19, but that we need more research to establish the extent of asymptomatic transmission," the WHO chief said at a virtual press conference from Geneva on Wednesday, Xinhua news agency reported.

"That research is ongoing, and we're seeing more and more research being done," he added.

Saying that the world has been achieving a lot in knowing the new virus, the WHO chief told reporters that "there's still a lot we don't

"WHO's advice will continue to evolve as new information becomes available," he said.

Tedros stressed that the most critical way to stop transmission is to find, isolate and test people with symptoms, and trace and quarantine their contacts.

"Many countries have succeeded in suppressing transmission and controlling the virus doing exactly this," Tedros said.

Meanwhile, Michael Ryan, executive director of WHO Health Emergencies Program, said Wednesday that the COVID-19 pandemic is still evolving.

"If we look at the numbers... this pandemic is still evolving. It is growing in many parts of the world," he said. "We have deep concerns that health systems of some countries are struggling, under a huge strain and require our support, our help and our solidarity."

He said "each and every country has a different combination of risks and opportunities, and it's really down to national authorities to carefully consider where they are in the pandemic."

In Europe, the risk issue now are about travels and the opening of the schools, around risk management, mass gathering, surveillance and contact tracing, said the WHO official.

In Southeast Asian countries, where to a great extent transmissions have been under control, governments are more concerned about the re-emergence of clusters, while in South America, the issue of PPE for health workers has not gone away, said Ryan.

As regards Africa, Ryan said the death rates have been very low in the past week, but the health system can be overwhelmed, as it would have to cope with other diseases such as malaria.