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Scientists warn of overlooked danger from coronavirus-spreading airborne microdroplets – CTV News

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TORONTO —
Physical distancing and frequent handwashing are not enough to fully protect against airborne transmission of the novel coronavirus, hundreds of scientists say.

Virus-carrying microdroplets pose more of a danger than is currently being communicated, the scientists argue in a new medical commentary, and the result is that poor ventilation is easing the path of the pandemic.

The commentary has been accepted for publication in the journal Clinical Infectious Diseases. It is signed by 239 scientists from 32 countries and a wide variety of science and engineering disciplines, according to a statement from the Queensland University of Technology (QUT) in Australia.

“We are concerned that people may think they are fully protected by following the current recommendations, but in fact, additional airborne precautions are needed to further reduce the spread of the virus,” lead author and QUT air quality expert Lidia Morawska said in the statement.

MICRODROPLETS EXPLAINED

It is not controversial to say that the virus that causes COVID-19 can spread through exhaled airborne droplets. This is why physical distancing was one of the earliest individual measures urged to stop the spread of the virus, because putting space between people allows for particles to fall to the ground rather than latch on to another person.

It is also normal for viruses to be passed through droplets. Measles, for example, has an airborne transmission pathway that poses far more of a danger than has thus far been found with COVID-19.

“I can be in a room with measles, and leave, and somebody walks in hours later and they can get measles,” Dr. Sumon Chakrabati, an infectious diseases physician based in Missisauga, Ont., said Monday on CTV News Channel.

The World Health Organization says the droplets that carry SARS-CoV-2 can be spread through actions including coughing, sneezing and speaking, and recommends that everyone keep a one-metre distance from others. Many countries, including Canada, have gone farther, recommending a distance of two metres.

However, there are signs that the smallest microdroplets can travel beyond the two-metre limit. One American study found that they can move three metres in 12 seconds, and a fourth metre as they linger in the air for up to a minute. Morawska said that there is significant evidence that microdroplets can travel even farther – into the tens of metres – especially when indoors.

“Studies by the signatories and other scientists have demonstrated beyond any reasonable doubt that viruses are exhaled in microdroplets small enough to remain aloft in the air and pose a risk of exposure beyond [one to two metres] by an infected person,” she said.

“Hand-washing and social distancing are appropriate, but … insufficient to provide protection from virus-carrying respiratory microdroplets released into the air by infected people.”

‘IS THERE A DANGER THERE?’

Advice from public health experts in Canada and elsewhere has largely downplayed the risk of airborne transmission of the virus, even as evidence mounts that it is a real threat. In one study cited in the commentary as an example, droplets were found to be the most likely source of transmission among three dining parties at a restaurant in China, in a case where surveillance video footage showed no direct or indirect contact between the groups.

The debate over droplets has been playing out since the pandemic took hold. Dr. Colin Furness, a Toronto-based infection control epidemiologist, described it as “a pretty serious fight, intellectually,” but said the commentary is unlikely to lead to significant changes in virus protection thinking.

“The concern is ‘Are we ignoring those small droplets? Is there a danger there? Are our interventions maybe not enough?'” he said Monday on CTV News Channel.

“It could be that a smaller dose, those smaller droplets, actually matter for [COVID-19] because it’s so good at getting a toehold in your body once it gets in there.”

In Chakrabati’s view, the possibility of airborne transmission is overshadowed by the evidence that Canada and other countries have been able to slow the spread of the virus with the current precautions and restrictions.

“Are there situations where the two metres is a bit too little, for example a karaoke bar or a choir, where you’re singing and your voice is propelling? Perhaps,” he said.

“But I think for the most part, the recommendations that have been there since the beginning are the ones that are truly preventing the spread of this virus.”

REDUCING THE RISK

Morawska said that effective ventilation systems are the best way to reduce the spread of microdroplets. She said the most effective systems minimize the use of recirculated air by bringing in as much clean air from outdoors as possible, and that even opening doors and windows can make a major difference.

These ventilation techniques can be augmented with the use of air filtration and exhaust devices, as well as ultraviolet (UV) lights that kill germs. Another way to lessen the risk of microdroplet transmission is to avoid situations of overcrowding, especially on public transport and in public buildings, Morawka said.

Furness agreed with the suggestion to use UV lights in air filtration systems, saying that there could be a “renaissance” in this practice because the light can be effective against the virus in a way that physical filters cannot.

“I think we will probably see a resurgence in the use of UV light within air circulation systems, because UV light will kill viruses and it doesn’t really matter how small they are,” he said.

Face masks do not play a role in protecting against microdroplets, Furness said, because the droplets are so small that they can fit through the holes in most masks.

“If we were really concerned about aerosol, if we were really concerned about airborne, we would also be finding that wearing face coverings typically didn’t have that much of an effect – but the evidence says that they do,” he said.

“It’s not that we dramatically need to change what we are doing, it’s a question of trying to better understand our adversary and better understand what some of those risks may be.”

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Biden’s vaccine pledge ups pressure on rich countries to give more

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The United States on Thursday raised the pressure on other Group of Seven leaders to share their vaccine hoards to bring an end to the pandemic by pledging to donate 500 million doses of the Pfizer coronavirus vaccine to the world’s poorest countries.

The largest ever vaccine donation by a single country will cost the United States $3.5 billion but Washington expects no quid pro quo or favours for the gift, a senior Biden administration official told reporters.

U.S. President Joe Biden‘s move, on the eve of a summit of the world’s richest democracies, is likely to prompt other leaders to stump up more vaccines, though even vast numbers of vaccines would still not be enough to inoculate all of the world’s poor.

G7 leaders want to vaccinate the world by the end of 2022 to try to halt the COVID-19 pandemic that has killed more than 3.9 million people and devastated the global economy.

A senior Biden administration official described the gesture as a “major step forward that will supercharge the global effort” with the aim of “bringing hope to every corner of the world.” “We really want to underscore that this is fundamentally about a singular objective of saving lives,” the official said, adding that Washington was not seeking favours in exchange for the doses.

Vaccination efforts so far are heavily correlated with wealth: the United States, Europe, Israel and Bahrain are far ahead of other countries. A total of 2.2 billion people have been vaccinated so far out of a world population of nearly 8 billion, based on Johns Hopkins University data.

U.S. drugmaker Pfizer and its German partner BioNTech have agreed to supply the U.S. with the vaccines, delivering 200 million doses in 2021 and 300 million doses in the first half of 2022.

The shots, which will be produced at Pfizer’s U.S. sites, will be supplied at a not-for-profit price.

“Our partnership with the U.S. government will help bring hundreds of millions of doses of our vaccine to the poorest countries around the world as quickly as possible,” said Pfizer Chief Executive Albert Bourla.

‘DROP IN THE BUCKET’

Anti-poverty campaign group Oxfam called for more to be done to increase global production of vaccines.

“Surely, these 500 million vaccine doses are welcome as they will help more than 250 million people, but that’s still a drop in the bucket compared to the need across the world,” said Niko Lusiani, Oxfam America’s vaccine lead.

“We need a transformation toward more distributed vaccine manufacturing so that qualified producers worldwide can produce billions more low-cost doses on their own terms, without intellectual property constraints,” he said in a statement.

Another issue, especially in some poor countries, is the infrastructure for transporting the vaccines which often have to be stored at very cold temperatures.

Biden has also backed calls for a waiver of some vaccine intellectual property rights but there is no international consensus yet on how to proceed.

The new vaccine donations come on top of 80 million doses Washington has already pledged to donate by the end of June. There is also $2 billion in funding earmarked for the COVAX programme led by the World Health Organization (WHO) and the Global Alliance for Vaccines and Immunization (GAVI), the White House said.

GAVI and the WHO welcomed the initiative.

Washington is also taking steps to support local production of COVID-19 vaccines in other countries, including through its Quad initiative with Japan, India and Australia.

(Reporting by Steve Holland in St. Ives, England, Andrea Shalal in Washington and Caroline Copley in Berlin; Writing by Guy Faulconbridge and Keith Weir;Editing by Leslie Adler, David Evans, Emelia Sithole-Matarise, Giles Elgood and Jane Merriman)

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Vaccines donated by the United States and China

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Both the United States and China have pledged large donations of COVID-19 vaccines to countries around the world. Washington has promised 80 million doses, three-quarters of which will be delivered via the international vaccine initiative COVAX, in what has been seen as an effort to counter China’s widening vaccine diplomacy. It began deliveries last week.

China had shipped vaccines to 66 countries in the form of aid, according to state news agency Xinhua. Beijing has not disclosed an overall figure for its donations but Reuters calculations based on publicly available data show at least 16.57 million doses have been delivered. China has also pledged to supply 10 million doses to COVAX.

VACCINES DONATED BY U.S. (plan for the first 25 mln):

Regional partners and priority recipients

COUNTRY/TERRITORY PLEDGED DELIVERED

Including Canada, Mexico, 1 mln to S.Korea in June

South Korea, West Bank and

Gaza, Ukraine, Kosovo,

Haiti, Georgia, Egypt,

Jordan, India, Iraq, Yemen,

United Nations

TOTAL 6 mln 1 mln

Allocations through COVAX

South and Central America

COUNTRY/TERRITORY PLEDGED DELIVERED

Brazil, Argentina, Colombia,

Costa Rica, Peru, Ecuador,

Paraguay, Bolivia,

Guatemala, El Salvador,

Honduras, Panama, Haiti,

Dominican Republic and other

Caribbean Community

(CARICOM) countries

TOTAL 6 mln

Asia

COUNTRY/TERRITORY PLEDGED DELIVERED

India, Nepal, Bangladesh,

Pakistan, Sri Lanka,

Afghanistan, Maldives,

Malaysia, Philippines,

Vietnam, Indonesia,

Thailand, Laos, Papua New

Guinea, Taiwan, and the

Pacific Islands

TOTAL 7 mln

Africa

COUNTRY/TERRITORY PLEDGED DELIVERED

To be selected in

coordination with the

African Union

TOTAL 5 mln

VACCINES DONATED BY CHINA (source – Reuters calculations and official data):

Asia Pacific

COUNTRY/TERRITORY PLEDGED DELIVERED

Afghanistan 400,000

Bangladesh Second batch of First batch of 500,000 delivered

600,000 on May 12

Brunei 52,000 in Feb

Cambodia 1.7 mln as of April 28

Kyrgyzstan 150,000 in March

Laos 300,000 in Feb

800,000 in late March

300,000 in late April

Maldives 200,000 in early March

Mongolia 300,000 in late February

Myanmar 500,000 in early May

Nepal 800,000 in late March

1 mln in early June

Pakistan 500,000 in early Feb

250,000 in Feb

500,000 in March

Philippines 600,000 in late Feb

400,000 in late March

Sri Lanka 600,000 at end March

500,000 in late May

Thailand 500,000 in May

500,000 in June

Timor-Leste 100,000 100,000 in early June

TOTAL 11.052 million

Africa

COUNTRY/TERRITORY PLEDGED DELIVERED

Angola 200,000 in late March

Algeria 200,000 200,000 in Feb

Botswana 200,000 in April

Cameroon 200,000 in April

Congo 100,000 100,000 in March

Egypt 600,000 in March

Ethiopia 300,000 in late March

Equatorial Guinea 100,000 in Feb

Guinea 200,000 in early March

Mozambique 200,000 in late Feb

Namibia 100,000 by early April

Niger 400,000 in late March

Sierra Leone 240,000 by late May

Togo 200,000 in April

Uganda 300,000

Zimbabwe 200,000 in Feb

200,000 in March

100,000 in May

TOTAL 3.74 million

South America

COUNTRY/TERRITORY PLEDGED DELIVERED

Bolivia 100,000 in late Feb

100,000 in late March

Venezuela 500,000 in early March

TOTAL 700,000

Europe & Middle East

COUNTRY/TERRITORY PLEDGED DELIVERED

Belarus 100,000 in Feb

300,000 in May

Georgia 100,000 at end April

Iran 250,000 at end February

Iraq 50,000 in early March

Montenegro 30,000 in early March

North Macedonia 100,000 in May

Syria 150,000 in late April

TOTAL 1.08 million

 

(Reporting by Roxanne Liu and Ryan Woo in Beijing and Cooper Inveen in Dakar; Additional reporting by MacDonald Dzirutwe in Harare, Asif Shahzad in Islamabad, Gopal Sharma in Kathmandu; Editing by Edwina Gibbs)

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Coronavirus Worldwide right now

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Here’s what you need to know about the coronavirus now:

Australia’s Melbourne to exit lockdown

Australia’s second largest city Melbourne will exit a hard lockdown as planned on Thursday night, Victoria state authorities said, although some restrictions on travel and gatherings would likely remain for another week.

After two weeks in a strict lockdown that forced people to remain at home except for essential business, Melbourne’s five million residents will get more freedom to step outside from 11:59 p.m. local time (1359 GMT) on Thursday.

However, people must stay within 25 km (15 miles) of their homes, officials said, in an effort to stop transmission during an upcoming long weekend. There will also be a total ban on house gatherings and masks will be mandatory indoors.

Deliveries of Thai-made AstraZeneca vaccines delayed

Malaysia and Taiwan are expecting deliveries of AstraZeneca vaccines manufactured in Thailand to be delayed, officials said, the latest countries to report a holdup with orders from the Thai plant.

The delay comes amid concerns over AstraZeneca’s distribution plans in Southeast Asia, which depends on 200 million doses made by Siam Bioscience, a company owned by Thailand’s king that is making vaccines for the first time.

Any questions about Siam Bioscience meeting production targets are sensitive because King Maha Vajiralongkorn is its sole owner. Insulting Thailand’s monarchy is a crime punishable by up to 15 years in prison.

Indonesia aims to speed up vaccinations

President Joko Widodo said on Wednesday he hoped Indonesia’s vaccination rollout will hit one million shots a day by July, as authorities opened up inoculations to anyone aged over 18 in Jakarta to contain increased transmission in the capital.

Health officials in the world’s fourth most populous country, which aims to vaccinate 181.5 million people by next year, are trying to speed up the rollout after facing some supply issues.

The president said he wanted vaccinations to hit a targeted 700,000 doses a day this month and then rise again.

Singapore finds Delta most prevalent among variants

Singapore has found the Delta variant of the coronavirus to be the most prevalent among local cases of variants of concern (VOCs), according to health ministry data, highlighting its level of infectiousness.

There were 449 local cases with VOCs as of May 31, of which 428 were the Delta variant first detected in India and nine of the Beta variant first identified in South Africa.

Singapore reported its 34th death due to COVID-19, taking its toll from the pandemic beyond the 33 casualties recorded during the 2003 Severe Acute Respiratory Syndrome outbreak.

U.S. forming expert groups on lifting travel restrictions

The Biden administration is forming expert working groups with Canada, Mexico, the European Union and the United Kingdom to determine how best to safely restart travel after 15 months of pandemic restrictions, a White House official said on Tuesday.

Another U.S. official said the administration will not move quickly to lift orders that bar people from much of the world from entering the United States because of the time it will take for the groups to do their work.

The groups will be led by the White House COVID Response Team and the National Security Council and include the Centers for Disease Control and other U.S. agencies.

 

(Compiled by Linda Noakes; Editing by Giles Elgood)

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