Tag: Covid-19 Vaccine

Seeing is Believing: Effectiveness of Face Masks – FAU College of Engineering and Computer Science Researchers Use Flow Visualization to Qualitatively Test Facemasks and Social Distancing

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Newswise — Currently, there are no specific guidelines on the most effective materials and designs for facemasks to minimize the spread of droplets from coughs or sneezes to mitigate the transmission of COVID-19. While there have been prior studies on how medical-grade masks perform, data on cloth-based coverings used by the vast majority of the general public are sparse.

Research from Florida Atlantic University’s College of Engineering and Computer Science, just published in the journal Physics of Fluids, demonstrates through visualization of emulated coughs and sneezes, a method to assess the effectiveness of facemasks in obstructing droplets. The rationale behind the recommendation for using masks or other face coverings is to reduce the risk of cross-infection via the transmission of respiratory droplets from infected to healthy individuals.

Researchers employed flow visualization in a laboratory setting using a laser light sheet and a mixture of distilled water and glycerin to generate the synthetic fog that made up the content of a cough-jet. They visualized droplets expelled from a mannequin’s mouth while simulating coughing and sneezing. They tested masks that are readily available to the general public, which do not draw away from the supply of medical-grade masks and respirators for healthcare workers. They tested a single-layer bandana-style covering, a homemade mask that was stitched using two-layers of cotton quilting fabric consisting of 70 threads per inch, and a non-sterile cone-style mask that is available in most pharmacies. By placing these various masks on the mannequin, they were able to map out the paths of droplets and demonstrate how differently they perform.

Results showed that loosely folded facemasks and bandana-style coverings stop aerosolized respiratory droplets to some degree. However, well-fitted homemade masks with multiple layers of quilting fabric, and off-the-shelf cone style masks, proved to be the most effective in reducing droplet dispersal. These masks were able to curtail the speed and range of the respiratory jets significantly, albeit with some leakage through the mask material and from small gaps along the edges.

Importantly, uncovered emulated coughs were able to travel noticeably farther than the currently recommended 6-foot distancing guideline. Without a mask, droplets traveled more than 8 feet; with a bandana, they traveled 3 feet, 7 inches; with a folded cotton handkerchief, they traveled 1 foot, 3 inches; with the stitched quilted cotton mask, they traveled 2.5 inches; and with the cone-style mask, droplets traveled about 8 inches.

“In addition to providing an initial indication of the effectiveness of protective equipment, the visuals used in our study can help convey to the general public the rationale behind social-distancing guidelines and recommendations for using facemasks,” said Siddhartha Verma, Ph.D., lead author and an assistant professor who co-authored the paper with Manhar Dhanak, Ph.D., department chair, professor, and director of SeaTech; and John Frakenfeld, technical paraprofessional, all within FAU’s Department of Ocean and Mechanical Engineering. “Promoting widespread awareness of effective preventive measures is crucial at this time as we are observing significant spikes in cases of COVID-19 infections in many states, especially Florida.”

When the mannequin was not fitted with a mask, they projected droplets much farther than the 6-foot distancing guidelines currently recommended by the United States Centers for Disease Control and Prevention. The researchers observed droplets traveling up to 12 feet within approximately 50 seconds. Moreover, the tracer droplets remained suspended midair for up to three minutes in the quiescent environment. These observations, in combination with other recent studies, suggest that current social-distancing guidelines may need to be updated to account for aerosol-based transmission of pathogens.

“We found that although the unobstructed turbulent jets were observed to travel up to 12 feet, a large majority of the ejected droplets fell to the ground by this point,” said Dhanak. “Importantly, both the number and concentration of the droplets will decrease with increasing distance, which is the fundamental rationale behind social-distancing.”

The pathogen responsible for COVID-19 is found primarily in respiratory droplets that are expelled by infected individuals during coughing, sneezing, or even talking and breathing. Apart from COVID-19, respiratory droplets also are the primary means of transmission for various other viral and bacterial illnesses, such as the common cold, influenza, tuberculosis, SARS (Severe Acute Respiratory Syndrome), and MERS (Middle East Respiratory Syndrome), to name a few. These pathogens are enveloped within respiratory droplets, which may land on healthy individuals and result in direct transmission, or on inanimate objects, which can lead to infection when a healthy individual comes in contact with them.

“Our researchers have demonstrated how masks are able to significantly curtail the speed and range of the respiratory droplets and jets. Moreover, they have uncovered how emulated coughs can travel noticeably farther than the currently recommended six-foot distancing guideline,” said Stella Batalama, Ph.D., dean of FAU’s College of Engineering and Computer Science. “Their research outlines the procedure for setting up simple visualization experiments using easily available materials, which may help healthcare professionals, medical researchers, and manufacturers in assessing the effectiveness of face masks and other personal protective equipment qualitatively.”

Pandemic threatens to veer out of control in U.S., public health experts say

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By Alvin Powell from the The Harvard GazetteHarvard public health experts said the nation’s COVID-19 epidemic is getting “quite out of hand” and that, with cases rising rapidly in the hardest-hit states and a two-week lag between infection and hospitalization, the situation appears set to worsen quickly.

“I have this awful feeling of déjà vu, like it’s March all over again,” said William Hanage, associate professor of epidemiology at the Harvard T.H. Chan School of Public Health.

Hanage, who spoke with reporters during a conference call Thursday morning, said that hospitals are nearing capacity in Arizona and Houston and are likely to be stressed elsewhere soon. And, in contrast to the nation’s early spike in COVID-19 cases that were concentrated in a few states, the current surge is much more widespread and so has greater potential to take off.

“The increases that we’re seeing right now have the capacity to cause far more disease in the future,” Hanage said.

Barry Bloom, the Joan L. and Julius H. Jacobson Research Professor of Public Health, who also fielded reporters’ questions Thursday, said other countries have shown that the epidemic can be contained by acting swiftly when cases appear. Even Italy, once on the verge of health system collapse, has regained control of its epidemic, Bloom said. Italy on Tuesday reported just 113 new cases and 18 deaths.

“If you only look at what you see today, you’re three weeks behind the curve. … It’s trying to imagine what will be three weeks from now … that should be determining policy.”— Barry Bloom, Harvard Chan School

“When political leaders wait until it gets really bad, that’s where we are now,” Bloom said. “If you only look at what you see today, you’re three weeks behind the curve. … It’s trying to imagine what will be three weeks from now — rather than what you see today — that should be determining policy.”

Hanage said he understands political leaders’ reluctance to reimpose lockdowns, but with few tools to fight the coronavirus and more moderate steps like masking and hand-washing most effective when numbers are also more moderate, a shutdown may turn out to be what’s needed.

“Let me be clear: I do not like shutdowns. But if they’re the only thing to prevent a worse catastrophe, you have to use them,” Hanage said.

A bright spot in the current epidemic is that the age of those contracting COVID-19 appears to be declining. Hanage said that he didn’t view it as a sign of the epidemic evolving, but rather a marker of testing being more widespread and catching more cases than during the March-April spike. Though younger people have better survival rates, that good news is tempered by the fact that we’ve been largely ineffective at keeping the virus away from those most susceptible for severe illness: the elderly and people with pre-existing conditions. But that may nonetheless mean there is a window of opportunity to suppress the epidemic before it takes hold among those more vulnerable populations.

“Let me be clear: I do not like shutdowns. But if they’re the only thing to prevent a worse catastrophe, you have to use them.”— William Hanage, Harvard Chan School

“If there is a window of action, it’s now,” Hanage said.Hanage struck a similar note on lower death rates in the current spike, saying deaths lag behind cases, so we should wait for a few weeks before concluding that anything different is going on.

Bloom said the difference between the U.S. and nations where the pandemic appears to be controlled is that those countries had uniform national policies and didn’t lift lockdowns until case numbers were very low. The fact that some of them have experienced new outbreaks — like the recent spate of cases in Beijing — is to be expected. Once the local epidemic is controlled, easing the lockdown will inevitably lead to new cases. The strategy then is to use testing to quickly identify cases and use contact tracing and isolation to contain outbreaks before they become widespread. In a state like California, with 7,000 new cases reported Tuesday, tracing the contacts of each positive test becomes a monumental task.

Rather than flinging the doors wide, the two said reopening should more closely resemble refining the shutdown, letting some things resume with safeguards in place that can be tightened should cases rise. Leaders should consider risk versus value to society in deciding what to reopen and when. For instance, bars, casinos, and churches, where people are crammed together and which have been shown to be hotspots of infection in some instances, may need to stay closed in order to keep the overall infection rate in the community low enough that we can safely reopen places with broad societal benefit, Bloom and Hanage said.

“We should be wanting to be able to open schools, and schools should have a higher priority, arguably, than other parts of the economy,” Hanage said. “What those [other parts of the economy to reopen] are, ought to be debated. … What we should be thinking about in reopening is not reopening everything in a safe way, but which things we want to reopen and being able to do that without enhancing community transmission.”

Even well-honed strategies will fail if citizens are noncompliant, however, Bloom said. In New York City, contact tracing programs have run into people not answering phones or refusing to isolate after hearing they’ve been exposed to infection. “If people are ignoring the epidemic, it’s going to be very hard to control,” Bloom said, “and leadership should be inspiring people to be more cautions.”

Will India Have A Covid-19 Vaccine By Aug 15?

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Indian Council of Medical Research (ICMR) head Dr Balram Bhargava on July 2 wrote to all 12 trial sites for the Covid-19 vaccine candidate, Covaxin, that all clinical trials had to be completed by August 15, in time for a public launch. Bioethics experts, however, have questioned how all three phases of testing for a vaccine candidate yet to even begin human trials can be crunched into a timeframe of a month.

What is Covaxin? It has been developed by the company Bharat Biotech India (BBIL) in collaboration with ICMR’s National Institute of Virology (NIV). It is an “inactivated” vaccine — one made by using particles of the Covid-19 virus that were killed, making them unable to infect or replicate. Injecting particular doses of these particles serves to build immunity by helping the body create antibodies against the dead virus, according to BBIL.

Is ICMR serious? The August 15 deadline given by the Indian Council of Medical Research (ICMR) for the launch of the indigenous Covid-19 vaccine being jointly developed by Bharat Biotech International (BBIL) — called Covaxin — has raised a storm within the scientific and medical community about the unrealistic timeline. That apart, it appears even the company may be unable to meet the target. Here’s why:

What ICMR wants: The ICMR has written a letter to 12 select hospitals across the country, practically warning them that “non-compliance will be viewed very seriously” if they failed to enrol human test subjects by next week Tuesday. The country’s governing body for medical research said that this measure was being taken “in view of the public health emergency due to Covid-19 pandemic” and that BBIL was “working expeditiously to meet the target”.

Really now? However, BBIL CMD Dr Krishna Ella, in an interview to The New Indian Express said on Thursday that he expects the “vaccine to be available early 2021“. In fact, BBIL, in its filing to the Clinical Trial Registry of India (CTRI) has stated that follow-ups for the clinical trial will be conducted on the 14th, 28th, 104th and 194th day — which clearly means a timeline of beyond 6 months. Additionally, the company lists the date of enrolment for the first phase of clinical trials from July 13 — almost a week after the ICMR’s deadline for enrolment.

Scrunch & crunch: Vaccine development is a long drawn process, usually spread over a number of years to determine any side-effects. Human clinical trials are a three phase process — starting from a small batch of healthy humans, usually between 40-50, moving on to a larger pool of over 100 with variations on dosage and frequency before the final phase, wherein randomly selected thousands or perhaps hundreds of thousands of volunteers are administered the vaccine. Under fire: While independent experts have been aghast at the ICMR’s vaccine-by-deadline approach, the governing body’s chairperson of ethics advisory committee Vasantha Muthuswamy conceded (as reported by Scroll) that “a month to decide whether to release a vaccine is a very short time” and that even if the vaccine was fast-tracked, “it will take a minimum of one year“.

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