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Here’s where (and how) you are most likely to catch COVID – new study

To discover your risk of catching coronavirus for any given situation, try our COVID-19 Aerosol Transmission Estimator.

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Two years into the pandemic, most of us are fed up. COVID case rates are higher than they’ve ever been and hospitalisation rates are once again rising rapidly in many countries.

Against this bleak picture, we yearn to get back to normal. We’d like to meet friends in a pub or have them over for dinner. We’d like our struggling business to thrive like it did before the pandemic. We’d like our children to return to their once-familiar routine of in-person schooling and after-school activities. We’d like to ride on a bus, sing in a choir, get back to the gym, or dance in a nightclub without fear of catching COVID.

Which of these activities is safe? And how safe exactly? These were the questions we sought to answer in our latest research.

SARS-CoV-2, the virus that causes COVID, spreads mainly by airborne transmission. So the key to preventing transmission is to understand how airborne particles behave, which requires knowledge from physics and chemistry.

Air is a fluid made up of invisible, rapidly and randomly moving molecules, so airborne particles disperse over time indoors, such as in a room or on a bus. An infected person may exhale particles containing the virus, and the closer you are to them, the more likely you are to inhale some virus-containing particles. But the longer the period you both spend in the room, the more spread out the virus will become. If you are outdoors, the space is almost infinite, so the virus doesn’t build up in the same way. However, someone can still transmit the virus if you’re close to them.

Viral particles can be emitted every time an infected person breathes, but especially if their breathing is deep (such as when exercising) or involves vocalisation (such as speaking or singing). While wearing a well-fitting mask reduces transmission because the mask blocks the release of virus, the unmasked infected person who sits quietly in a corner is much less likely to infect you than one who approaches you and starts a heated argument.

All variants of SARS-CoV-2 are equally airborne, but the chance of catching COVID depends on the transmissibility (or contagiousness) of the variant (delta was more contagious than previous variants, but omicron is more contagious still) and on how many people are currently infected (the prevalence of the disease). At the time of writing, more than 97% of COVID infections in the UK are omicron and one person in 15 is currently infected (prevalence 6.7%). While omicron appears more transmissible, it also seems to produce less severe illness, especially in vaccinated people.

Likelihood of becoming infected

In our study, we have quantified how the different influences on transmission change your risk of getting sick: viral factors (transmissibility/prevalence), people factors (masked/unmasked, exercising/sitting, vocalising/quiet) and air-quality factors (indoors/outdoors, big room/small room, crowded/uncrowded, ventilated/unventilated). We did this by carefully studying empirical data on how many people became infected in superspreader events where key parameters, such as the room size, room occupancy and ventilation levels, were well-documented and by representing how transmission happens with a mathematical model.

The new chart, adapted from our paper and shown below, gives a percentage likelihood of becoming infected in different situations.

Table showing the risk of catching COVID based on various factors.
Risk of catching COVID. Author provided

A surefire way to catch COVID is to do a combination of things that get you into the dark red cells in the table. For example:

  • Gather together with lots of people in an enclosed space with poor air quality, such as an under-ventilated gym, nightclub or school classroom

  • Do something strenuous or rowdy such as exercising, singing or shouting

  • Leave off your masks

  • Stay there for a long time.

To avoid catching COVID, try keeping in the green or amber spaces in the table. For example:

  • If you must meet other people, do so outdoors or in a space that’s well-ventilated or meet in a space where the ventilation is good and air quality is known

  • Keep the number of people to a minimum

  • Spend the minimum possible amount of time together

  • Don’t shout, sing or do heavy exercise

  • Wear high-quality, well-fitting masks from the time you enter the building to the time you leave.

While the chart gives an estimated figure for each situation, the actual risk will depend on the specific parameters, such as exactly how many people are in a room of what size. If you fancy putting in your own data for a particular setting and activity, you can try our COVID-19 Aerosol Transmission Estimator.

Trish Greenhalgh receives funding from MRC, ESRC, NIHR, Wellcome Trust, Health Foundation, Scottish Government

Jose-Luis Jimenez receives funding from NASA, US NSF, US DOE, NOAA, and the Sloan Foundation.

Shelly Miller receives funding from the National Science Foundation, the Alfred P. Sloan Foundation, the US EPA. She is affiliated with the International Society for Indoor Air Quality and Climate, the American Association for Aerosol Research and is an Associate Editor for the peer-reviewed journal Environmental Science & Technology.

Zhe Peng receives funding from US NSF and NASA.

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VIRI: Enrollment Complete in FORTRESS Trial; Results Expected in September 2022…

By David Bautz, PhD
NASDAQ:VIRI
READ THE FULL VIRI RESEARCH REPORT
Business Update
FORTRESS Trial Fully Enrolled; Topline Results in September 2022
On…

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By David Bautz, PhD

NASDAQ:VIRI

READ THE FULL VIRI RESEARCH REPORT

Business Update

FORTRESS Trial Fully Enrolled; Topline Results in September 2022

On April 28, 2022, Virios Therapeutics, Inc. (NASDAQ: VIRI) announced that it has completed enrollment of 425 fibromyalgia patients into the Phase 2b FORTRESS (Fibromyalgia Outcome Research Trial Evaluating Synergistic Suppression of Herpes Simplex Virus-1) trial, a randomized, double blind, placebo controlled study of IMC-1. The primary endpoint of the trial is reduction in pain and secondary endpoints include change in fatigue, sleep disturbance, global health status, and patient functionality (NCT04748705). An outline of the trial is shown below.

In parallel with the FORTRESS trial, Virios is continuing the chronic toxicology studies of IMC-1 in two animal species. The results of these studies are required by regulators before Virios will be allowed to dose patients for one year or more, which is the plan for the Phase 3 program. The results of the chronic toxicology studies should be known around the time of the completion of the FORTRESS trial, thus the company should be able to move into a final Phase 3 program following completion of the current study, pending positive results.

Testing Combination Antiviral Therapy for the Treatment of Long COVID

In February 2022, Virios announced a collaboration with the Bateman Horne Center (BHC) to test combination antiviral therapy for the treatment of Long COVID. Following an infection with SARS-CoV-2, the virus that causes COVID-19, approximately 30% of patients will experience symptoms that last for weeks or months, which is referred to as Long COVID. The range of symptoms varies from patient to patient, however the most commonly reported (from a recent meta analysis) were fatigue (58%), headache (44%), attention disorder (27%), hair loss (25%), and dyspnea (24%) (Lopez-Leon et al., 2021).

The main theories for what might be causing ...

Full story available on Benzinga.com

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Type-I interferon stops immune system ‘going rogue’ during viral infections

Hamilton, ON (May 17, 2022) – McMaster University researchers have found not only how some viral infections cause severe tissue damage, but also how…

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Hamilton, ON (May 17, 2022) – McMaster University researchers have found not only how some viral infections cause severe tissue damage, but also how to reduce that damage.

Credit: Georgia Kirkos/McMaster University

Hamilton, ON (May 17, 2022) – McMaster University researchers have found not only how some viral infections cause severe tissue damage, but also how to reduce that damage.

 

They have discovered how Type I interferon (IFN) stops the immune system ‘going rogue’ and attacking the body’s own tissues when fighting viral infections, including COVID-19.

 

Their paper was published in the journal PLOS Pathogens today.

  

Senior author Ali Ashkar said IFN is a well-known anti-viral signalling molecule released by the body’s cells that can trigger a powerful immune response against harmful viruses.

 

“What we have found is that it is also critical to stop white blood cells from releasing protease enzymes, which can damage organ tissue. It has this unique dual function to kick start an immune response against a viral infection on the one hand, as well as restrain that same response to prevent significant bystander tissue damage on the other,” he said.

 

The research team investigated IFN’s ability to regulate a potentially dangerous immune response by testing it on both flu and the HSV-2 virus, a highly prevalent sexually transmitted pathogen, using mice. Data from COVID-19 patients in Germany, including post-mortem lung samples, was also used in the study.

 

“For many viral infections, it is not actually the virus that causes most of the tissue damage, it is our heightened immune activation towards the virus,” said Ashkar, a professor of medicine at McMaster.

  

First co-author of the study and PhD student Emily Feng said: “Our body’s immune response is trying to fight off the virus infection, but there’s a risk of damaging innocent healthy tissue in the process. IFNs regulates the immune response to only target tissues that are infected.

 

“By discovering the mechanisms the immune system uses that can inadvertently cause tissue damage, we can intervene during infection to prevent this damage and not necessarily have to wait until vaccines are developed to develop life-saving treatments,” she added.

 

“This applies not just to COVID-19, but also other highly infectious viruses such as flu and Ebola, which can cause tremendous and often life-threatening damage to the body’s organs,” said first study co-author Amanda Lee, a family medicine resident. 

 

Ashkar said the release of harmful proteases is the result of a ‘cytokine storm’, which is life-threatening inflammation sometimes triggered by viral infections. It has been a common cause of death in patients with COVID-19, but treatment has been developed to prevent and suppress the cytokine storm.

 

Ashkar said that steroids like dexamethasone are already used to rein in an extreme immune response to viral infections. The authors used doxycycline in their study, an antibiotic used for bacterial infections and as an anti-inflammatory agent, inhibits the function of proteases causing the bystander tissue damage.

 

Lee added: “This has the potential in the future to be used to alleviate virus-induced life-threatening inflammation and warrants further research.” 

 

The study was funded by the Canadian Institutes of Health Research.

 

-30-

 

Editors:

Pictures of Ali Ashkar and Emily Feng may be found at https://bit.ly/3wmSw0D

  

 

 


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mRNA vaccines like Pfizer and Moderna fare better against COVID-19 variants of concern

A comparison of four COVID-19 vaccinations shows that messenger RNA (mRNA) vaccines — Pfizer-BioNTech and Moderna — perform better against the World…

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A comparison of four COVID-19 vaccinations shows that messenger RNA (mRNA) vaccines — Pfizer-BioNTech and Moderna — perform better against the World Health Organization’s variants of concern (VOCs) than viral vector vaccines — AstraZeneca and J&J/Janssen. Although they all effectively prevent severe disease by VOCs, the research, publishing May 17th in the open access journal PLOS Medicine, suggests that people receiving a viral vector vaccine are more vulnerable to infection by new variants.

Credit: Carlos Reusser Monsalvez, Flickr (CC0, https://creativecommons.org/publicdomain/zero/1.0/)

A comparison of four COVID-19 vaccinations shows that messenger RNA (mRNA) vaccines — Pfizer-BioNTech and Moderna — perform better against the World Health Organization’s variants of concern (VOCs) than viral vector vaccines — AstraZeneca and J&J/Janssen. Although they all effectively prevent severe disease by VOCs, the research, publishing May 17th in the open access journal PLOS Medicine, suggests that people receiving a viral vector vaccine are more vulnerable to infection by new variants.

By March 2022, COVID-19 had caused over 450 million confirmed infections and six million reported deaths. The first vaccines approved in the US and Europe that protect against serious infection are Pfizer-BioNTech and Moderna, which deliver genetic code, known as mRNA, to the bodies’ cells, whereas Oxford/AstraZeneca and J&J/Janssen are viral vector vaccines that use a modified version of a different virus — a vector — to deliver instructions to our cells. Three vaccines are delivered as two separate injections a few weeks apart, and J&J/Janssen as a single dose.

Marit J. van Gils at the University of Amsterdam, Netherlands, and colleagues, took blood samples from 165 healthcare workers, three and four weeks after first and second vaccination respectively, and for J&J/Janssen at four to five and eight weeks after vaccination. Samples were collected before, and four weeks after a Pfizer-BioNTech booster.

Four weeks after the initial two doses, antibody responses to the original SARS-CoV-2 viral strain were highest in recipients of Moderna, followed closely by Pfizer-BioNTech, and were substantially lower in those who received viral vector vaccines. Tested against the VOCs – Alpha, Beta, Gamma, Delta and Omicron – neutralizing antibodies were higher in the mRNA vaccine recipients compared to those who had viral vector vaccines. The ability to neutralize VOCs was reduced in all vaccine groups, with the greatest reduction against Omicron. The Pfizer-BioNTech booster increased antibody responses in all groups with substantial improvement against VOCs, including Omicron.

The researchers caution that their AstraZeneca group was significantly older, because of safety concerns for the vaccine in younger age groups. As immune responses tend to weaken with age, this could affect the results. This group was also smaller because the Dutch government halted use for a period.

van Gils concludes, “Four COVID-19 vaccines induce substantially different antibody responses.”

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In your coverage, please use this URL to provide access to the freely available paper in PLOS Medicine:

http://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1003991

Citation: van Gils MJ, Lavell A, van der Straten K, Appelman B, Bontjer I, Poniman M, et al. (2022) Antibody responses against SARS-CoV-2 variants induced by four different SARS-CoV-2 vaccines in health care workers in the Netherlands: A prospective cohort study. PLoS Med 19(5): e1003991. https://doi.org/10.1371/journal.pmed.1003991

 

Author Countries: The Netherlands, United States

 

Funding: This work was supported by the Netherlands Organization for Scientific Research (NWO) ZonMw (Vici grant no. 91818627 to R.W.S., S3 study, grant agreement no. 10430022010023 to M.K.B.; RECoVERED, grant agreement no. 10150062010002 to M.D.d.J.), by the Bill & Melinda Gates Foundation (grant no. INV002022 and INV008818 to R.W.S. and INV-024617 to M.J.v.G.), by Amsterdam UMC through the AMC Fellowship (to M.J.v.G.) and the Corona Research Fund (to M.K.B.), and by the European Union’s Horizon 2020 program (RECoVER, grant no. 101003589 to M.D.d.J). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.


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