Are appropriate precautions being recommended for avoiding COVID-19 infection?
Yes. The recommended actions given by public health officials are correct for preventing infection by a virus such as COVID-19.
My concern is that many people are handling this virus as if it is a bacterium. These are two very different infectious agents. A bacterium, such as E. coli, can replicate independently outside a living organism and frequently contaminates food and inanimate surfaces from which it can replicate with common nutrients. A virus cannot replicate outside a cell and therefore must be transferred to living creatures to cause an infection and produces its progeny.
But there is still a fear by many that COVID-19 could be on doorknobs, tabletops, pens, pencils, on clothing, food or in swimming pools and could start an infection.
That is not the case. Because the virus needs to get inside a cell to replicate, this can only be possible if, for example, it can be carried after a short time to the nose or mouth where it can infect a person.
However the amount of infectious virus can be so little that the components of the natural rapid-acting innate immune system in the nose and mouth would destroy it readily. But, if the amount of infectious virus is high or continually introduced it could overwhelm the innate immune system and cause infection. That is why the length of time that one is exposed is a component of the transmission process as well as whether the infectious virus is in enough quantity (eg. in the air) to be transmitted to a person.
In contrast, a bacterium can exist outside a living cell for long periods of time and replicate to high number without being inside a cell. That is why a small amount of a bacterium can create a serious infectious disease (such as E coli in food) if not stopped in its transmission.
Since COVID-19 is a virus, that distinction is important and certainly explains the misunderstanding given to this virus if present on everyday surfaces, on food, packages, etc. where it would not be a source of infection. Therefore, some procedures being followed (such as leaving out packages and mail, washing food products, sharing pens, touching surfaces) are those recommended for preventing infection by disease-causing bacteria, not by a virus.
It seems much more important to have the public understand, above all, that the major transmission of COVID-19 is by the air through respiratory droplets or aerosols that have contact with the nose and mouth.
When is the best time to test for COVID- 19 infection?
What we know about the virus is that, after the initial infection, symptoms and/or virus replication will become evident within 3-5 days and last up to 10-14 days. The length of time that someone will be contagious with COVID-19 depends on how quickly and effectively their immune system controls the virus. Within the time frame of 3-14 days, testing works best to identify those infected so that quarantining can be instituted and contact tracing begun.
Are you concerned about the lack of verified information being shared around the COVID-19 pandemic?
Yes, absolutely. The public often depends on social media which can have sensationalized stories about finding the virus under different conditions. Recently, when I went for dinner at a friend’s home (with all the precautions followed) my friend announced that she was going to prepare the salmon well-done since she had just read that the virus can be in salmon. As I have mentioned before, COVID-19 has a lipid/sugar coat that would not let it survive in water no less in fish.
Unlike the polio virus that has a protective protein coat, COVID-19 would not survive very long in water. In this regard, some of us remember the closing of swimming pools during the polio epidemic. Now we should assume wearing masks has the same important message. Today, some individuals I know will not go into a public swimming pool because of the fear of getting COVID-19. That was an appropriate warning for the poliovirus – not for COVID-19. Unfortunately, this misinformation influences people to not listen to public health experts. Moreover, some newspapers will print findings that have not been published or that have been reported at a meeting or at a press conference without the appropriate review of public health experts. We must be aware of this false messaging.
What about being outside, particularly going to a beach with large groups of people?
There has not been, to my knowledge, any definite proof of COVID-19 infection when someone is alone outside. Nevertheless, meeting in groups at beaches can be a source of infection. However, generally, because of the winds off the sea, the viruses, like smoke at a beach, are diluted in the air. Infection does not take place with the resulting very low levels of virus in floating respiratory products. As Dr. Michael Osterholm, Director of the Center for Infectious Disease Research and Policy at the University of Minnesota, has said: “The solution to pollution is dilution.” This is why outdoor restaurants should be safe particularly with 6 feet distancing and, for extra precaution, wearing a mask if in close contact with someone.
What medicine can we hope to have to combat this virus?
We really have very few if any effective antiviral drugs. The drugs for HIV/AIDS are, fortunately, an exception but their development took many years. There are some medicines used for the flu, but in most cases these will reduce the symptoms somewhat but not quickly eliminate the virus. A major reason that viruses challenge the development of medicines is that, unlike bacteria, a virus needs to enter the cell and capture the machinery of that cell to reproduce itself. The medicines would need to either stop the virus at the cell surface before it can enter (that might be achieved with neutralizing antibodies) or, in most cases, eliminate the virus inside the infected cell. In this case, the medicine may go into normal cells affect them.
So, a drug developed against viruses like COVID- 19 has to be shown to be non-toxic to people when used as medicine in clinical trials. A drug that destroys the virus inside a cell would also enter normal cells as well and could destroy them leading to uncomfortable symptoms. Also, an antiviral drug, such as interferon, may be effective in controlling the virus but lead to such toxic effects that people will not take them. The side effects could be harmful. Pharmaceutical companies must face this challenge of developing antiviral drugs that do not have uncomfortable side effects.
I guess this is a reason we don’t have medicine for the common cold?
Yes. A drug that kills the coid virus inside a cell could also be toxic to normal cells. Finding the non-harmful drug is the challenge. It can be very difficult, take a long time or just not be possible.
What other issues are involved in the development of an effective vaccine?
Vaccine researchers must be certain that enhancing the immune response against the virus will not increase the immune responses against normal cells and tissues leading to harmful side effects. This could be the normal cell damage that, as I noted to you before, can give the severe symptoms of COVID-19. Also, we are in a situation in which the time for a vaccine is so dramatically emphasized that some of us worry that vaccines will be accepted that are not as effective or safe as they could be. There is a concept in immunology called “Original antigenic sin.” It refers to the immune system’s preference to use immunologic memory from a previous infection and not respond strongly to a second different version of a protein or vaccine. If one rushes to get a vaccine that might be only somewhat effective, that first vaccine might prevent the individual from getting a very effective strong immune response from a future vaccine — one that might provide long-lasting immunity. However, I remain confident that our research scientists and public health officials will be mindful of this possibility.
So, what else can we do to avoid the infection and the disease?
Exercise is an excellent way of arming the immune system against an incoming virus. Walking, running, swimming, cycling, pilates, can keep the immune system activated so that infection with COVID-19 might occur without even any symptoms. In this regard, it is estimated that 40-50% of infected people do not show signs of the virus. That is why we have to be most careful of our interactions personally.
Why do many young people not get ill from the virus?
We believe it is because their immune system is more balanced. They do not produce large amounts of cellular factors such as cytokines which are meant to fight the virus but, in doing so, are toxic to the infected individual. Importantly, studying these asymptomatic individuals may give us insight into medicines that will be helpful for those who are sick.
Is there anything noted in the laboratory that could influence our understanding of the virus?
It is helpful to know that Barbara Schmidt, a former postdoctoral fellow in my laboratory, now working in Germany, has found that this virus replicates to very high levels in cells. But, for each infectious particle there are 60,000 noninfectious particles. Thus, when the viruses enter the nose or mouth during an infection, the noninfectious particles will be vying to bind to the virus attachment site on a cell and should interfere with a live virus infection. Therefore, we should feel confident that just wearing a mask (or any barrier on the face) should be protective against a COVID- 19 infection as emphasized by doctors and public health officials.
What is your explanation for the symptoms that are being seen in some people after the COVID-19 infection seems to have been controlled or eliminated?
The effect that COVID-19 has on some infected people has been alarming since it was assumed that once the virus was controlled, the symptoms would disappear. Unfortunately, what we are witnessing is the onset of a post-viral immune syndrome which often looks like chronic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME). These conditions are related to a chronically activated immune system that has no mechanism for quieting down. The viral cause of the disease has been controlled or eliminated but the activated immune system remains stimulated and produces antiviral toxic products that give rise to fatigue, weakness and muscle aches. I once suggested calling CFS the chronic immune activation syndrome (CIAS) to avoid the fatigue moniker which is so often seen in many illnesses.
What is the final message that you would like to leave with our readers?
My final advice on COVID-19 is very much in line with the public health message: wear masks, avoid large inside groups, maintain six feet distancing and wash your hands. COVID-19 is a challenge but its transmission can be effectively prevented by following these simple guidelines.