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Covid-19 is primarily airborne: Lancet

(Asian News Hub) – A report in The Lancet journal has dismissed the predominant scientific view that SARS-CoV-2, the coronavirus that causes Covid-19, is not an airborne pathogen.

Areport published in the journal The Lancet has dismissed the predominant scientific view that SARS-CoV-2, the coronavirus that causes Covid-19, is not an airborne pathogen. The authors of the report have listed 10 reasons for their claim that “SARS-CoV-2 is transmitted primarily by the airborne route”.

The paper, written by six experts from the UK, the US and Canada, argues that there are “insufficient grounds for concluding that a pathogen is not airborne” while “the totality of scientific evidence indicates otherwise”. The experts called for urgent modification in the Covid-19 safety protocol.

CORONAVIRUS IS AIRBORNE: 10 REASONS CITED BY THE RESEARCHERS

  1. “Superspreading events account for substantial SARS-CoV-2 transmission; indeed, such events may be the pandemic’s primary drivers,” they said. Detailed analyses of human behaviours and interactions, room sizes, ventilation, and other variables, the authors said, are consistent with airborne spread of SARS-CoV-2 and the same cannot be adequately explained by droplets or fomites.
  2. Long-range transmission of SARS-CoV-2 between people in adjacent rooms but never in each other’s presence has been documented in quarantine hotels, the paper said.
  3. The experts argued that from 33 per cent to 59 per cent of all Covid-19 cases could be attributed to asymptomatic or presymptomatic transmission of SARS-CoV-2 from people who are not coughing or sneezing. They said this supported a predominantly airborne mode of transmission.
  4. Transmission of SARS-CoV-2 is higher indoors than outdoors and is substantially reduced by indoor ventilation.
  5. The paper said nosocomial infections (those that originate in a hospital) had been documented even at places where healthcare professionals used personal protective equipment (PPE) designed to protect against droplet but not aerosol exposure.
  6. The experts said viable SARS-CoV-2 has been detected in the air. In laboratory experiments, SARS-CoV-2 stayed infectious in the air for up to 3 hours. They rejected the argument that SARS-CoV-2 was bit cultivated from air arguing that measles and tuberculosis, two primarily airborne diseases, had never been cultivated from room air.
  7. SARS-CoV-2 has been identified in air filters and building ducts in hospitals with COVID-19 patients; such locations could be reached only by aerosols, they said.
  8. The experts cited studies involving infected caged animals that showed transmission of SARS-CoV-2 via an air duct.
  9. Another argument of the experts was that no study to our knowledge provided strong or consistent evidence to refute the hypothesis of airborne SARS-CoV-2 transmission.
  10. Their final argument was that there was limited evidence to support other dominant routes of transmission- i.e. respiratory droplet or fomite.

The claim of the experts, if proven and accepted, could have massive implications on counter-Covid-19 strategy across the world. This may require the people to wear mask even inside their homes, and possibly at all times.

The current understanding is that SARS-CoV-2 spreads through smaller aerosols that stay suspended in air or through fomites, the surfaces where the virus gets deposited, and could be picked by a health person. Gravity pulls down heavier droplets reducing the chances of infection considerably.

But if an infectious virus is mainly airborne, an individual could potentially be infected when they inhale aerosols produced when an infected person exhales, speaks, shouts, sings, sneezes, or coughs, the experts said. This changes the way the world should fight coronavirus pandemic.

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Serosurvey would determine impact of possible 3rd Covid wave on children: DAK

(Asian News Hub) – Doctors Association Kashmir (DAK) on Saturday said serosurvey of pediatric population in the valley would determine the impact of possible third Covid-19 wave on children.

Serosurvey of children will give us a fair estimate of their vulnerability in predicted third wave,” said DAK President and influenza expert Dr Nisar ul Hassan.

“Serosurvey involves testing blood samples of individuals for antibodies that are developed after an infection,” he said.

“This will give us an idea about the percentage of pediatric population who might have developed natural immunity.”

Dr Hassan said recently, a serosurvey of general population including children aged 7 to 17 years has been completed in Kashmir, the results of which are awaited.  The sample size per district in the age group 7 to 11 was 40 and it was 80 in 12-17 age group.

“The survey needs to be extended to the age group of 0 to 6 years and the sample size per district should be 500 to 1000 to get a clearer picture of the actual percentage of children who have developed immunity against Covid-19,” he said.

Dr Hassan said there are speculations that children would be affected more than adults in possible third wave as this is the population group in which there is no vaccine yet.

“However, various serosurveys have dismissed the claim that the next wave will be affecting children exclusively,” he said.

“A pediatric serological study conducted by AIIMS, New Delhi at five different sites found that 55.7 percent children had developed antibodies,” DAK President said.

“The study found that seroprevalence of children and adults in the same regions were almost similar.”

“Another study conducted by PGI Chandigarh revealed that 69 percent of children had antibodies against Covid-19,” he said.

“These children had remained either asymptomatic or mildly symptomatic during the infection.”

“The data of the two surveys prove that children have acquired natural immunity against the virus and it is highly unlikely that the third wave will affect children more than adults,” said Dr Nisar.

“This is a big relief. Because the apprehensions expressed by several health experts about the third wave primarily targeting children had left people worried,” he said.

“But, we can’t derive conclusions on the data from other regions. We need to have our own data based on which decisions can be made ahead of the feared third wave,” he added.

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Medical Science

Israel reports Pfizer COVID-19 vaccine effectiveness against infection down to 40%

(Asian News Hub) – The Health Ministry said Thursday that the effectiveness of the Pfizer COVID-19 vaccine in preventing infection and mild symptoms has dropped to 40%, according to new data collected over the past month as the delta variant spreads in Israel.

In a televised address, Prime Minister Naftali Bennett meanwhile called on Israelis who haven’t been vaccinated to do so as soon as possible.

“The Israeli government is investing billions so that there is a vaccine available in every location in the country, and there are still a million Israelis who simply refuse to be vaccinated,” he said. “The vaccine refusers are endangering their health, their surroundings and all Israeli citizens. If a million Israelis continue to be unvaccinated, this will force the others to shut themselves in at home.”

The effectiveness of the vaccine in preventing hospitalizations and severe symptoms stands at 88% and 91%, respectively, the ministry said.

With inputs from Haaretz

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Medical Science

Scientists discover more than 30 viruses frozen in ice, most never seen before

(Asian News Hub) – A group of scientists discovered ancient viruses frozen in two ice samples taken from the Tibetan Plateau in China, and most of them are unlike anything ever seen before.

The findings, published Wednesday in the journal Microbiome, came from ice cores taken in 2015 that scientists said began to freeze at least 14,400 years ago.

“These glaciers were formed gradually, and along with dust and gases, many, many viruses were also deposited in that ice,” Zhi-Ping Zhong, lead author and researcher at the Ohio State University Byrd Polar and Climate Research Center, said in a statement. “The glaciers in western China are not well-studied, and our goal is to use this information to reflect past environments. And viruses are a part of those environments.”

When researchers analyzed the ice, they found genetic codes for 33 viruses. Of the 33, genetic codes for four of them showed they are part of virus families that typically infect bacteria. Up to 28 were novel, meaning they had never before been identified.

The group said it doesn’t believe the viruses originated from animals or humans but came from the soil or plants. The scientists said roughly half of them survived because of the ice.

“These are viruses that would have thrived in extreme environments,” said Matthew Sullivan, co-author of the study and director of Ohio State’s Center of Microbiome Science.

“These viruses have signatures of genes that help them infect cells in cold environments – just surreal genetic signatures for how a virus is able to survive in extreme conditions.”

Sullivan said the technology used to study microbes and viruses inside the ice would lead to looking for similar genetic sequences in other extreme ice environments, possibly on Mars.

Senior author of the study Lonnie Thompson said the discovery of the viruses in glaciers of ice will help researchers understand how they respond to climate change.

“We know very little about viruses and microbes in these extreme environments and what is actually there,” Thompson said. 

“The documentation and understanding of that is extremely important.”

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