According to a new study, Coronavirus loses 90 per cent of its ability to infect people within 20 minutes of being in the air.

The research re-emphasised the importance of physical distancing and mask-wearing to be the most effective means of preventing short-range Covid transmission.

“People have been focused on poorly ventilated spaces and thinking about airborne transmission over metres or across a room. I’m not saying that doesn’t happen, but I think still the greatest risk of exposure is when you’re close to someone,” said Prof Jonathan Reid, director of Aerosol Research Centre and the study’s lead author.

“When you move further away, not only is the aerosol diluted down, there’s also less infectious virus because the virus has lost infectivity (as a result of time),” he said.

It is well established that the virus is spread through droplets and aerosols produced in the lungs. But the researchers at the University of Bristo’s Aerosol Research Centre developed a mechanism that allows for an accurate simulation of how long the virus can survive when it is in the air.

Also read |&nbsp;W<a href="https://www.wionews.com/world/who-says-over-50-of-europeans-on-track-to-contract-omicron-variant-of-coronavirus-443861">HO says over 50% of Europeans on track to contract Omicron variant of coronavirus</a>

The <a href="https://www.medrxiv.org/content/10.1101/2022.01.08.22268944v1.full.pdf">study</a>, which is yet to be peer-reviewed, is the first of its kind to simulate how exactly coronavirus travels in the air after it has been exhaled, The Guardian reported.

To understand what happens to the virus when it becomes airborne, the researchers developed an apparatus to generate virus-containing particles and allowed them to float between two electric rings for anywhere between five seconds and 20 minutes in a tightly controlled environment.

According to the study, when the viral particles leave the lungs, they quickly lose water and the lower levels of carbon dioxide in the environment result in a rapid increase in pH. This affects the virus’s ability to infect human cells.

Also read |<a href="https://www.wionews.com/world/omicron-was-in-canadian-wastewater-in-november-before-it-was-found-in-south-africa-443845">&nbsp;Omicron was in Canadian wastewater in November before it was found in South Africa</a>

In a typical office environment, where humidity of the surrounding area is generally lower than 50 per cent, the virus became half as infectious within five seconds, after which the loss in infectivity became slower and more gradual.

The biologists saw the same effects all three Sars-CoV-2 variants, including Alpha. They hope to start experiments with the Omicron variant in the coming weeks.

(With inputs from agencies)

According to a new study, Coronavirus loses 90 per cent of its ability to infect people within 20 minutes of being in the air. The research re-emphasised the importance of physical distancing and mask-wearing to be the most effective means of preventing short-range Covid transmission.

According to a new study, Coronavirus loses 90 per cent of its ability to infect people within 20 minutes of being in the air. The research re-emphasised the importance of physical distancing and mask-wearing to be the most effective means of preventing short-range Covid transmission. “People have been focused on poorly ventilated spaces and thinking about airborne transmission over metres or across a room. I’m not saying that doesn’t happen, but I think still the greatest risk of exposure is when you’re close to someone,” said Prof Jonathan Reid, director of Aerosol Research Centre and the study’s lead author. “When you move further away, not only is the aerosol diluted down, there’s also less infectious virus because the virus has lost infectivity (as a result of time),” he said. It is well established that the virus is spread through droplets and aerosols produced in the lungs. But the researchers at the University of Bristo’s Aerosol Research Centre developed a mechanism that allows for an accurate simulation of how long the virus can survive when it is in the air. Also read | WHO says over 50% of Europeans on track to contract Omicron variant of coronavirus The study, which is yet to be peer-reviewed, is the first of its kind to simulate how exactly coronavirus travels in the air after it has been exhaled, The Guardian reported. To understand what happens to the virus when it becomes airborne, the researchers developed an apparatus to generate virus-containing particles and allowed them to float between two electric rings for anywhere between five seconds and 20 minutes in a tightly controlled environment. According to the study, when the viral particles leave the lungs, they quickly lose water and the lower levels of carbon dioxide in the environment result in a rapid increase in pH. This affects the virus’s ability to infect human cells. Also read | Omicron was in Canadian wastewater in November before it was found in South Africa In a typical office environment, where humidity of the surrounding area is generally lower than 50 per cent, the virus became half as infectious within five seconds, after which the loss in infectivity became slower and more gradual. The biologists saw the same effects all three Sars-CoV-2 variants, including Alpha. They hope to start experiments with the Omicron variant in the coming weeks. (With inputs from agencies)

Covid loses 90% of ability to infect within 20 minutes of being airborne: Study

Stressing that the Covid virus may continue to transmit for a very long time, senior WHO official Poonam Khetrapal Singh says the level of immunity in a community, through vaccination and previous infection, will determine whether it will become endemic in the long run.

WHO's South-East Asia region regional director added that there is need to get to a situation where "we are fully in control of the virus, and not the virus in control of us".

The endemic stage is when a population learns to live with a virus, very different from the epidemic stage when the virus overwhelms a population.

Populations where more people were previously infected and where vaccination coverage is high are expected to be less impacted by the virus in the future than other populations, Singh told PTI in an interview.

"The COVID-19 virus is expected to continue to transmit for a very long time. A multitude of factors will decide whether the virus will become endemic in the long run, chief among them is the level of immunity in a community, both through vaccination and previous infection, she said.

Also read |&nbsp;<a href="https://www.wionews.com/india-news/india-records-18795-fresh-covid-19-cases-lowest-in-six-months-416546">India records 18,795 fresh COVID-19 cases, lowest in six months</a>

On the granting of emergency use authorisation (EUA) for the indigenously developed Covaxin, she said Bharat Biotech's dossier seeking WHO's Emergency Use Listing (EUL) is being reviewed by technical experts and "we can expect a decision when the process is complete".

Also read |&nbsp;<a href="https://www.wionews.com/world/covid-pandemic-ceos-of-pfizer-and-moderna-say-life-will-be-back-to-normal-in-a-year-416527">Covid pandemic: CEOs of Pfizer and Moderna say life will be back to normal in a year</a>

Discussing the role of booster doses to tackle waning immunity, Singh pointed out that cases and deaths in all countries are predominantly being driven by unvaccinated people. Using vaccines for booster doses constricts supply to countries where millions are still waiting for their first dose, she said.

"Hence, WHO has called for a time-limited moratorium on COVID-19 booster doses until the end of 2021. This is to allow for at least 40 per cent of the population of each country - including those most at risk and health workers - to be vaccinated. We must remember that no one is safe till everyone is safe."

Also read |&nbsp;<a href="https://www.wionews.com/world/cant-go-unvaccinated-president-biden-gets-vaccine-booster-shot-416490">'Can't go unvaccinated': President Biden gets vaccine booster shot</a>

She said there is currently no conclusive evidence that COVID-19 vaccine efficacy against severe disease and death wanes significantly over time. The vaccines, the expert emphasised, have remained effective in preventing severe disease and death.

"However, WHO has not ruled out that boosters for some population groups may be warranted in future. WHO's recommendations on boosters will be guided by the scientific evidence, which is still evolving," she said.

"To make a recommendation on the use of booster doses for the general population, more data is needed on optimal timing, safety and dosage of booster doses, which may differ between vaccine products. More extensive research is needed to study the effect of booster doses in the body." 
According to Singh, eradication is unlikely but what we can do is to prevent or minimise deaths, hospitalisations, tragedy and social, economic and health loss due to this pandemic.

Current evidence, she said, shows that protection levels around the world remain low and most people continue to be susceptible to the virus.

"WHO continues to recommend a strong public health response based on risk assessment, and for people to continue to protect themselves by getting vaccinated, maintaining physical distance, wearing a mask, avoiding poorly ventilated spaces, cleaning hands and following respiratory hygiene." 
 
Referring to the probability of a third Covid wave, Singh said another surge and how intense it will be will depend on all of us.

"If we together continue to adhere to public health and social measures and continue to vaccinate people as fast as possible, it will be hard for the virus to infect enough people to cause another wave," she said.

"From experience globally, there is enough evidence that the public health and social measures work, even against the Variants of Concern that are spreading more rapidly, and these measures are critical to limiting transmission of COVID-19 and reducing deaths. For the public health and social measures to be effective, they must be implemented well and timely and must be tailored to local settings and conditions." 
 
On India's decision to restart exporting COVID-19 vaccines, Singh said there is need for equity of vaccination administration globally to ensure that the most vulnerable such as frontline workers and the elderly are fully vaccinated.

"At the moment, several low and lower-middle-income countries are lagging behind in vaccinating their vulnerable populations. An equitable vaccine distribution will also help check the emergence of variants by halting the spread of the virus." 
 
Singh also noted that the pandemic has given "once-in-a-century opportunity" to strengthen the health system to build back better.

"We must invest in strengthening health system resilience to ensure health security and achieve universal health coverage. It means allocation of more resources for health and its efficient governance," she said.

Now is also the time for countries to take lessons from the pandemic to strengthen health systems in her view.

"Strong health systems that are primary healthcare-oriented, and which leave no one behind, create populations that are healthier, more productive and financially secure. Resilient health systems are the bedrock of emergency preparedness and response, and ensure that when acute events occur, essential health services can be maintained," Singh said.

Stressing that the Covid virus may continue to transmit for a very long time, senior WHO official Poonam Khetrapal Singh says the level of immunity in a community, through vaccination and previous infection, will determine whether it will become endemic in the long run.

Stressing that the Covid virus may continue to transmit for a very long time, senior WHO official Poonam Khetrapal Singh says the level of immunity in a community, through vaccination and previous infection, will determine whether it will become endemic in the long run. WHO's South-East Asia region regional director added that there is need to get to a situation where "we are fully in control of the virus, and not the virus in control of us". The endemic stage is when a population learns to live with a virus, very different from the epidemic stage when the virus overwhelms a population. Populations where more people were previously infected and where vaccination coverage is high are expected to be less impacted by the virus in the future than other populations, Singh told PTI in an interview. "The COVID-19 virus is expected to continue to transmit for a very long time. A multitude of factors will decide whether the virus will become endemic in the long run, chief among them is the level of immunity in a community, both through vaccination and previous infection, she said. Also read | India records 18,795 fresh COVID-19 cases, lowest in six months On the granting of emergency use authorisation (EUA) for the indigenously developed Covaxin, she said Bharat Biotech's dossier seeking WHO's Emergency Use Listing (EUL) is being reviewed by technical experts and "we can expect a decision when the process is complete". Also read | Covid pandemic: CEOs of Pfizer and Moderna say life will be back to normal in a year Discussing the role of booster doses to tackle waning immunity, Singh pointed out that cases and deaths in all countries are predominantly being driven by unvaccinated people. Using vaccines for booster doses constricts supply to countries where millions are still waiting for their first dose, she said. "Hence, WHO has called for a time-limited moratorium on COVID-19 booster doses until the end of 2021. This is to allow for at least 40 per cent of the population of each country - including those most at risk and health workers - to be vaccinated. We must remember that no one is safe till everyone is safe." Also read | 'Can't go unvaccinated': President Biden gets vaccine booster shot She said there is currently no conclusive evidence that COVID-19 vaccine efficacy against severe disease and death wanes significantly over time. The vaccines, the expert emphasised, have remained effective in preventing severe disease and death. "However, WHO has not ruled out that boosters for some population groups may be warranted in future. WHO's recommendations on boosters will be guided by the scientific evidence, which is still evolving," she said. "To make a recommendation on the use of booster doses for the general population, more data is needed on optimal timing, safety and dosage of booster doses, which may differ between vaccine products. More extensive research is needed to study the effect of booster doses in the body." According to Singh, eradication is unlikely but what we can do is to prevent or minimise deaths, hospitalisations, tragedy and social, economic and health loss due to this pandemic. Current evidence, she said, shows that protection levels around the world remain low and most people continue to be susceptible to the virus. "WHO continues to recommend a strong public health response based on risk assessment, and for people to continue to protect themselves by getting vaccinated, maintaining physical distance, wearing a mask, avoiding poorly ventilated spaces, cleaning hands and following respiratory hygiene." Referring to the probability of a third Covid wave, Singh said another surge and how intense it will be will depend on all of us. "If we together continue to adhere to public health and social measures and continue to vaccinate people as fast as possible, it will be hard for the virus to infect enough people to cause another wave," she said. "From experience globally, there is enough evidence that the public health and social measures work, even against the Variants of Concern that are spreading more rapidly, and these measures are critical to limiting transmission of COVID-19 and reducing deaths. For the public health and social measures to be effective, they must be implemented well and timely and must be tailored to local settings and conditions." On India's decision to restart exporting COVID-19 vaccines, Singh said there is need for equity of vaccination administration globally to ensure that the most vulnerable such as frontline workers and the elderly are fully vaccinated. "At the moment, several low and lower-middle-income countries are lagging behind in vaccinating their vulnerable populations. An equitable vaccine distribution will also help check the emergence of variants by halting the spread of the virus." Singh also noted that the pandemic has given "once-in-a-century opportunity" to strengthen the health system to build back better. "We must invest in strengthening health system resilience to ensure health security and achieve universal health coverage. It means allocation of more resources for health and its efficient governance," she said. Now is also the time for countries to take lessons from the pandemic to strengthen health systems in her view. "Strong health systems that are primary healthcare-oriented, and which leave no one behind, create populations that are healthier, more productive and financially secure. Resilient health systems are the bedrock of emergency preparedness and response, and ensure that when acute events occur, essential health services can be maintained," Singh said.

Covid virus expected to continue to transmit for a very long time, says WHO official

Patients infected with COVID-19 can transmit the deadly virus one to three days before showing symptoms of the disease. According to the latest study published by US centers for disease control and prevention. Watch report:

Understanding transmission of COVID-19: US study confirms threat of silent carriers