Questions on COVID-19

Coronavirus and the disease it causes, COVID-19, are unlike anything our health-care system has seen before. Dr. Chris Mody, MD, a professor and head of our Department of Microbiology, Immunology & Infectious Diseases, answers some of the most common questions about how you can protect yourself and others from the virus. 

Questions with an asterisk * are recently added

As a community, the best thing we can do to defeat this virus is to work together and remember that we are all working for the same purpose. The best way to do that is to follow Dr. Hinshaw’s advice. The worst thing that could happen is for everyone to go and do their own thing against Dr. Hinshaw’s advice. It is crucial to have a coordinated approach. We have seen the challenges some cities and countries have faced because they were not working together as a team.

When Dr. Hinshaw spoke on Monday (Apr. 27), it was the first time she talked about the possibility of going outside with a small group of friends while still maintaining social distance. Up to this point, we had been asked to avoid making contact with friends even while maintaining physical distancing. This is a big step! It will be a great thing for Albertans to get outside for a bit of socialization and fitness. Albertans need to be very proud of the work they have done so that people didn’t suffer because of an overwhelmed health-care system. We need to continue that by staying informed every day on updates from the Public Health office. Other things you can do to help your community is to check in on your elderly neighbours, support your local business, do not hoard things like groceries and stay home – especially if you are sick. Remember, we are all in this together.

This is a very complex question and in order to answer that question, we have to think of the big picture. The big picture is: How are we going to defeat this pandemic? Theoretically, there are a few different ways to defeat it:

  1. We contain the virus – We try and eliminate the virus from the human population. This means vigorously pursuing containment and allowing the virus to die (not spread) in every single person that becomes infected. A person gets the infection, self-isolates, the virus dies, and the person develops immunity and the virus does not continue to be transmitted. The WHO worked very hard at this approach in the early stages of the pandemic, but it was unfortunately unsuccessful. This approach will help, but it won’t be the thing that rids society of this problem
  2. A change in seasons Summer kills many viruses (e.g. influenza). Some still wonder if summer will kill COVID-19. However, as we start to learn more, it now seems unlikely because the virus causes infections in some parts of the world that are currently experiencing summer(southern hemisphere). Summer may not slow down COVID-19 like it does for influenza.
  3. We develop antivirals – When a patient is treated with an antiviral drug, the virus dies within them. It achieves the same goal as containment, but it does so through the use of drugs. We don’t have drugs now, but look forward to when they are available.
  4. Develop a vaccine – A vaccine will stop spread. People would receive some form of the virus and develop immunity to it. When they are immune, it is much less likely to cause severe infection, or any infection at all.
  5. COVID-19 becomes an endemic disease This means the virus stays with us forever. Although we hope this is not the case, it may occur until we get a vaccine. We anticipate a vaccine within the next 12-18 months. Some viruses like HIV or West Nile virus still do not have a vaccine and consequently they have become long-standing problems. Our hope is that COVID-19 is not one of those.
  6. Allow people to become infected and develop immunity This is a scary approach because more people will get sick and some will even die. However, this approach extinguishes the pandemic because the person that is infected cannot transmit it. It is important that they are not in contact with someone who is susceptible. Vaccines work this way, but in this case, it is done through natural and infectious immunity.

 

It is important to note that is what we are doing when we consider lifting restrictions. If we are going to lift restrictions and let the virus out, we need to be very smart about it. We need to do it strategically based on science and closely monitor what happens when a restriction is lifted. There is tremendous interest in Alberta among the public and leadership that we start to lift restrictions. Albertans need to understand what we are doing to the pandemic by lifting restrictions and we all need to be part of the team in order to defeat this virus.

As of Monday (Apr. 27), there are no studies that specifically address reinfection with COVID-19 at a population level. There are a few anecdotal reports where people who develop the disease fully recover and then get sick again, but it is very rare. So, we are left looking at studies done in highly related viruses. We have to look to coronaviruses that cause significant mortality like MERS and SARS.

A study was done in SARS which showed that people who developed the disease had the highest level of antibodies four months after infection. Unfortunately, those antibodies gradually wane. At six years, the vast majority of patients did not have detectable antibodies anymore. However, there is another type of immunity. In addition to antibody immunity, we have cellular immunity from T cells. Those same patients at six years continued to demonstrate cellular immunity to SARS even though they didn’t have antibody immunity. So, while we anticipate protection for a year or two from antibodies, cellular immunity might protect us even longer. The trouble is that we don’t know whether these tests correlate with protection from the virus. There are many studies taking place all over the world to try and figure this out as quickly as we can.

As a lung doctor, I think about how the particles are dispersed in the air. One of the important factors is not only how far the droplets go, but is there sufficient amount of virus to cause an infection. We are currently trying to figure out how many virus particles you have to be exposed to in order to develop an infection.

 More than one viral particle is necessary to cause infection. So, it is not just how close you are, but the concentration of virus. When you are in the wind, the droplets are dispersed by the turbulent airflow. So yes, it is possible for one droplet to go further than two metres. However, there are less particles and the low concentration of the virus is insufficient to cause infection. We believe that even in windy conditions, two metres is fine.

There are two forms of contact and two ways that we can contract COVID-19. One way is through droplet transmission – you send droplets into the environment when you cough, sneeze or talk. Respiratory droplets can spread as far as two metres from their source. These droplets can contact another person’s mouth, nose or respiratory tract and spread the infection.

The other way to contract the virus is through contact. In this case, droplets containing the virus fall onto a surface and contaminate the surface. Alternately, if you cough or sneeze into your hand, it contaminates your hand and then when you touch a surface, it contaminates that surface. Someone then touches the surface contaminating their hand, they then touch their face causing transmission of the virus and a new infection.

Thankfully, we have strategies to mitigate both of those approaches. The social distancing deals with droplet transmission because we know that droplets fall out of the air within two meters. Physical distancing deals with this mechanism of transmission. Mitigation against contact is to clean surfaces, wash your hands and do not touch your face. We know that COVID-19 is not spread through aerosol (tiny particles that stay in the air for a long time) other than in exceptional circumstances. Aerosol transmission is not driving this pandemic as it does for other viruses like measles

If you are within two metres of someone that has the virus and they produce an infected droplet that you breathe in, yes, you can acquire the virus. That is why we recommend staying two metres away from others. You are also more likely to contract the virus if you have prolonged contact with someone who has it, as opposed to passing by someone quickly. Nevertheless, it is recommended to keep a physical distance of two meters and cover your face, especially in crowded locations. It is crucial to adhere to these guidelines until the Medical Officer of Health thinks it is safe to lift the restrictions.

Studies have been done to look at how long the virus lives outside the body. It turns out that it depends on the nature of the surface. Different surfaces allow the virus to live for different lengths of time. For example, on a surface like copper, the virus can only live an hour or two. However, on plastic it can live for 24-48 hours. The good news is that by disinfecting surfaces with cleaning solutions (70 per cent alcohol, bleach, peroxide), you can decrease the survival time of the virus from one hour or one day to one minute. So, if you receive packages, spray or wipe them with disinfectant, and leave for a minute while the disinfectant works.

Wiping down surfaces that are potentially contaminated or wiping down packages that arrive at your door are both important to do. Wiping surfaces in your home that are touched by others is important. Early in the pandemic we learned that eating and serving utensils are a source of spreading the infection. Before COVID-19, I taught patients not to share drinking or eating utensils or toothbrushes within their household. I would now extend that to food serving utensils.  

We all need to take precautions in Alberta. If you are sick, you need to stay home as that protects your fellow co-workers. Physical distancing should be maintained. If you are in a workspace where you cannot maintain the two-metre distance, you should use a face covering. Additionally, we must be very cautious, using hand sanitizers often as well as other methods of disinfection.

We know the virus is prevalent in Alberta and that many people have become infected. Consequently, a single case report of a person working at an establishment does not implicate the establishment. They could have contracted the virus somewhere else. Once the establishment is cleaned and the person is in isolation, there is no reason to avoid the establishment. However, if multiple people become infected at an establishment, that should be investigated and strategies employed to mitigate. As the pandemic proceeds, we can expect to see more and more individual cases in people who happen to work at an establishment. This is expected. There is no place in Alberta that is completely safe, and we all need to do our part to stop the virus!

There has been conflicting information recently about wearing a mask. What is your advice? Will a mask help protect me while I’m at work or in public? 

The Chief Medical Officer of Health has indicated we should wear a face covering while in public. I support and advocate for that position, but I think it is useful and important for people to understand what the mask is actually doing.

Surgical masks were designed to protect patients in the operating room from acquiring organisms from the surgeon. Without a mask, the surgeon could spread droplets into the wound and cause a post-operative wound infection. Surgeons wear masks to protect their patients.

Likewise, when you use a mask, you are protecting others. A mask is not very effective at protecting you if you are wearing it. My fear is that people will think they are protected, fail to wash their hands and maintain physical distancing and thereby increase the chance of getting infected. Maintaining distance, washing your hands and using hand sanitizer are actually more important than wearing a mask if you are trying to protect yourself.

In the early stages of the pandemic, studies indicated that virus transmission occurred only when people had symptoms. Consequently, the approach was to tell people to stay home if they are sick. At that time, we didn’t think that pre-symptomatic (before symptoms occur) or asymptomatic (having no symptoms) transmission was an important way to spread of the virus. However, as more information has become available, we realized it is possible to spread the virus in the day or two prior to developing symptoms and, in rare circumstances, even when people have no symptoms during the course of infection. That presents a problem – how do we protect the public from transmission during the period where they have the virus and can spread it but they do not even know they have it? Wearing a mask will reduce the chance of spread during that time. As we continue to learn more about COVID-19 and its transmission, we adjust our approach.

Hand washing is better. Every time you wash your hands, you eliminate the virus (wash dead virus down the sink). The problem with gloves is that every time you touch a surface with a glove, there is the potential you could spread it to another surface using that same glove. Anything you touch with your gloved hands — like your phone, wallet or purse — is technically contaminated. You shouldn’t be touching your face, fiddling with your mask or doing anything else that you wouldn’t do with bare hands.

The false sense of security is also a worry. You are far better off touching a surface, using hand sanitizer or washing your hands, then wash again the next time you touch a public surface. There is also a risk when people take gloves out of the box that they contaminate the entire box. If you take gloves off incorrectly, you can contaminate yourself. So, you think you are protected, but you are not. It is more important to wash your hands.