Antiviral Drug Remdesivir for Coronavirus (COVID-19)
The U.S. Food and Drug Administration (FDA) issues Emergency Use Authorization (EUS) of antiviral drug Remdesivir to treat hospitalized patients with severe COVID-19 disease
What is Emergency Use Authorization (EUS)?
The issuance of an Emergency Use Authorization (EUS) is different from the U.S. Food and Drug Administration (FDA) approval. An emergency use authorization (EUA) by the FDA is a temporary authorization that is meant to provide access to medicine in an emergency.
Remdesivir use in COVID-19:
Recently, the U.S. Food and Drug Administration authorized the emergency use of the investigational antiviral drug remdesivir only to treat hospitalized patients with severe Covid-19 disease. It is the first authorized therapy drug for Covid-19 in the United States.
Remdesivir can be used for the treatment of suspected or laboratory-confirmed COVID-19 in adults and children hospitalized with severe disease. Severe disease is defined as patients with
- Low blood oxygen levels or
- Need oxygen therapy or
- Requiring intensive breathing support such as a mechanical ventilator
Clinical trials showed that remdesivir shortens the recovery times in people who have fallen ill from the new coronavirus compared to those given a placebo.
Remdesivir is administered intravenously by health care providers and there is limited information known so far about the safety and effectiveness of it.
Possible side effects of remdesivir include:
- Increased levels of liver enzymes
- Infusion-related reactions like
- Low blood pressure
- Nausea / vomiting
Multiple studies are still ongoing for the safety and efficacy of this investigational drug.
What are Viruses?
Viruses are primitive microscopic organisms that have existed for millions of years. They are unable to live without a “host”, i.e. they live within cells of another larger body (referred to as a host). All plants and animals are made up of cells. Every cell within plants and animals contains DNA, which forms genes. Viruses however can carry their genes in both DNA or a molecule similar to DNA called RNA. Viruses are very tiny simple organisms that are made up of either a strand of DNA or RNA wrapped in a coat of protein. They are incapable of living or reproducing on their own and must live within another organism.
How and where do viruses live and reproduce?
Viruses have a great ability to attach themselves to the cells of another organism (bacteria, plants, animals), injecting their DNA or RNA contents inside the host cell, taking over the operation of that cell using it to multiply itself i.e. make multiple copies of more viruses.
Why are viruses so harmful?
Throughout human existence we have been plagued by many viruses which have caused significant illness and death. Viral infection can lead to damage of various organs including brain, liver, heart, lung etc., that may cause individuals to be disabled, or can lead to death. Over time we have learned to combat potent viral diseases such as, measles, mumps, polio, and smallpox through the use of vaccines. Many of us are familiar with the seasonal flu (influenza) that typically occurs during the winter months. These viruses often cause fever, body aches, cough, sneezing, and can lead to respiratory distress, pneumonia, and death. In fact, many thousands of people die each year globally from seasonal influenza. Seasonal flu vaccines can help to reduce infection, illness and death.
What are coronaviruses?
Human Coronaviruses (CoV) were first identified about 60 years ago. They are a large family of RNA viruses that cause respiratory illnesses of varying severity from a mild common cold to more severe diseases such as pneumonia. Only seven coronaviruses are known to cause disease in humans, four of them are common and most frequently cause symptoms of the common cold. However, three of these viruses can cause severe, and sometimes fatal, respiratory infections. In recent years we have encountered two of these three viruses in the form of SARS-CoV (Severe acute respiratory syndrome) for which there was an outbreak in 2003, and MERS-CoV (Middle East respiratory syndrome), outbreak in 2012. The third virus, identified in 2019 is called SARS-CoV-2 (Coronavirus disease 2019, or COVID-19) and is responsible for the current pandemic.
Why is the new coronavirus so infectious?
Most flu viruses cause symptoms very early in the course of infection, i.e. an infected individual shows signs of illness (feeling unwell, lethargic, cough, fever) within a few days of exposure to the virus. It is at that point that the person is most infectious, and can spread the virus to others. However, the new coronavirus is different in that an infected individual may be pre-symptomatic (not show any signs of infection) for up to 2 weeks. During that time however, that infected individual could spread the virus to others through direct contact or respiratory droplets. It is this “stealth” behavior of the virus that makes it so infectious and potentially deadly.
Why is the new coronavirus so destructive?
Many individuals infected with a new coronavirus may show little or no symptoms of infection, but despite being pre-symptomatic or asymptomatic the virus maintains its ability to spread from person to person through respiratory droplets and direct contact. In symptomatic individuals the infection can proceed from mild flu-like symptoms and progress to sudden, severe lung inflammation, with difficulty breathing (respiratory distress), pneumonia, and death. In some cases blood clots can also develop in the lung. Other organs including the brain, heart, lung, and kidney can also be damaged by this infection. The extent of the disability that might occur from injury to these organs is at this time not fully understood.
Can face masks protect against COVID–19?
The wearing of face masks in high-risk environments such as hospital emergency rooms and nursing homes can help reduce the risk of infection and spread of COVID-19. The concept here is that face masks should provide a barrier between the person wearing the masks from those around them. One of the main ways that COVID–19 spreads is from exposure of heavy respiratory droplets from an infected individual. It is felt that the virus can remain in airborne for about 1-3 hours following a cough or sneeze, and hence wearing of properly fitting hospital grade face masks could potentially provide a barrier that might reduce inhalation of the heavy respiratory droplets that contain the virus. However, the use of home-made face (cloth) masks, in the general public is somewhat controversial.
How do homemade cloth masks compare to hospital grade masks?
Homemade masks are not medical devices, i.e. they have not been tested and regulated, and the porous nature of homemade masks are unlikely to provide complete protection against microscopic virus-sized particles. Also, homemade cloth masks are often loose fitting and so do not offer a good seal around the nose and mouth and will not be effective in blocking airborne virus particles that may be transmitted by coughing or sneezing. By comparison, surgical/hospital grade masks, particularly N95 masks, are designed to achieve a very close facial fit and efficient filtration of airborne particles, including viruses. However, note that the N95 designation implies an efficiency of at least 95%. Hence, if an N95 respirator mask provides 95% efficiency, a homemade device made of cotton (cloth), will not likely be as efficient.
Are there any scenarios where a homemade mask can/should be worn?
While, wearing homemade masks in the community has not been proven to protect the person wearing it, they may still help prevent the spread of the coronavirus by the following means:
- May be used as an additional measure to help cut down the spread of the novel coronavirus in situations where individuals can’t always ensure proper physical (social) distancing, i.e. may restrict distribution of respiratory droplets between individuals in close spaces
- By covering both mouth and nose with a homemade mask, it will help prevent spread of respiratory droplets from contaminating others and surfaces, and help reduce viral spread
- Reports show that the coronavirus can live in droplets in the air for up to one to three hours after an infected individual has left an area. Face masks will help prevent these droplets from getting into the air and infecting others, i.e. pre-symptomatic individuals who were unaware that they are infected with COVID-19, are less likely to distribute heavy respiratory droplets to others around them, while wearing a homemade mask.
- Homemade masks could be worn over a medical mask to help extend the use/reuse of the medical mask.
- Homemade masks may be helpful in reducing spread of heavy respiratory droplets during physical activity such as walking, running, and biking.
Is it necessary to always wear a homemade mask when leaving my home?
It is not necessary to wear homemade masks continually after you leave your home, as the masks could become soiled or contaminated with other bacteria and viruses, that will make the mask unsanitary. It is not necessary to wear a mask when walking in open spaces, or traveling in a car by yourself, or with other members of your household. Masks, however, may be most helpful in confined areas (such as grocery stores) particularly if social distancing is a concern.
Pros and cons of wearing a homemade mask?
- Homemade masks may restrict the distribution of respiratory droplets in the atmosphere and could potentially reduce the spread of COVID–19.
- They are cheap and easy to make.
- All family members can readily be supplied with masks
- Homemade mask can be fashioned with pockets to insert other masks or filters to improve effectiveness
- Cloth mask can be easily washed and kept clean and reused several times
- Non-medical masks have limitations with regards to blocking inhalation of viral particles
- Prolonged wearing of any mask can lead to moisture buildup on the inside of the mask, which can encourage the growth of bacteria and viruses, and lead to other types of infections.
- Frequent handling/re-positioning of the outside of the mask can lead to either contamination of the fingers and hands from a dirty mask, or vice versa, contamination of the mask with dirty hands.
- Homemade masks may create a false sense of security, that may encourage some to ignore social distancing, or frequent hand washing
Important considerations while wearing a mask?
- Wash your hands immediately before putting on any mask and immediately after taking it off
- To avoid contamination, do not handle the mask excessively while it is being worn (in addition to practicing good hand hygiene while wearing it)
- Ensure that the mask fits well on your face, without gaping spaces
- Do not wear a mask for extended periods of time without changing or washing them.
- Typically, if it is necessary to wear throughout the day, it should be changed approximately every 4 hours or sooner if the mask becomes damp or soiled
- Wash a homemade mask regularly
- Masks should not be shared with others
- Keep all used face masks separately and wash separately from other garments.
- To avoid spread within the environment and contaminating others, discard all medical and non-medical masks directly into a garbage bin
Should the public purchase a supply of surgical masks?
COVID–19 is a global pandemic that requires cooperation of all individuals including the general public to follow the rules of the local health authorities, as it relates to social distancing, hand washing, and avoid face touching. Almost 2 million people have already been infected with the virus, leading to serious illness requiring hospitalization and over 100,000 deaths. Hospital and front-line healthcare workers are overwhelmed with managing COVID-19 cases, and account for ~ 10% of COVID-19 cases. Currently, there is a shortage of personal protective equipment (including masks) to supply front-line health professionals dealing with COVID–19 patients in the emergency room, ICU, in-patient units, nursing home/long-term care facilities. For the public, privately purchasing surgical masks, will only add to the shortage of masks currently available for those on the front lines. Hence, hospital/surgical face masks and respirators (like N95 masks), must be kept for healthcare workers and others providing direct care to COVID-19 patients.
Be aware that in addition to hospital masks and N95 surgical respirators masks, complete protection can only be achieved when masks are used in combination with appropriate eye protection (e.g., face shield, goggles) to achieve full protection of the eyes, nose and mouth. Consequently, acquiring any of these additional protective devices will also contribute to shortage in these areas, which could see front-line healthcare workers working with inadequate equipment. Consequently, these types of protective equipment must be kept for healthcare providers.
Update on social distancing:
Since heavy respiratory droplets tend to fall on surfaces within 1-2 meters, the primary goal of social distancing is to protect against exposure, and reduce transmission/spread of viral particles contained within heavy respiratory droplets from individuals infected with COVID-19. Current recommendations therefore for social distancing are to remain 2 meters (approximately 6 feet), away from others (not living in your household).
However, there are additional considerations for widening the gap between individuals during physical activity such as walking, running or biking. Performing these activities 2 meters (6 feet) apart (side by side) would appear to be satisfactory, however, walking, running or biking in tandem i.e. one behind the next, can create a scenario whereby the trailing individual(s) may be exposed to heavy respiratory droplets emitted from the breath from the person in front, through “slipstream” airflow that carries the breath of the lead walker, runner or biker into the individuals behind. Consequently, a wider gap is required for those engaged in these types of cardiovascular activities. The current suggestion for tandem walking, running or riding is to remain about 4–5 m behind others when walking, 10 meters if running, at about 20 meters when engaged in a brisk ride. Walking, running or cycling in a staggered position, i.e. not directly behind the person in front, could also help to reduce the risk of exposure to heavy respiratory droplets carried in the slipstream of the person in front. Wearing a mask while engaged in these types of physical activity might be helpful to avoid dispersal or inhalation of heavy respiratory droplets.
Summary of use of facial masks and reducing risk of contracting Covid-19.
Prevention is better than cure; reduce your risk of developing COVID–19 by following by:
- Practice and encourage social distancing among others
- Wash your hands frequently.
- Avoid excess touching of your eyes, nose and mouth.
- Homemade face masks may not prevent inhalation of viral particles, but would reduce the chances of spreading the disease by reducing distribution of heavy respiratory droplets into the environment.
- Facial masks should be used only in certain scenarios, where proper social (physical) distancing is not ensured.
- Be aware of the need for increased physical distancing during subtypes of cardiovascular activity, including brisk walking, running, or cycling
Please be mindful of the risks that our front-line healthcare professionals are taking to care for those with COVID–19, and avoid purchasing and hoarding surgical masks and other personal protective equipment; as much as possible these should be reserved for healthcare professionals.
For further advice and resources, please visit: www.educateyourhealth.com