The Covid-19 disease caused by the novel coronavirus, Sars Cov 2, has caught the attention of even the usually careless in the population. And this is mainly because of the high transmissibility, as well as the fatality rates from the infection.
Current data shows that coronavirus is deadlier than another seasonal respiratory virus, the flu virus. In the U.S., the fatality rate of the seasonal flu is 0.1 percent. By contrast, the fatality rate of Covid-19 is currently estimated to be 1 percent. It goes without saying that Covid-19 is about ten times more lethal than the flu.
Further, data available from empirical research on the flu virus, gives us an appreciation of the startling difference between the two viruses. It is estimated that an average of 8.3 percent of the population will get sick from flu each season in the U.S., and when asymptomatics are further added to this number, the estimate could shoot up to 20 percent.
There is a paucity of information, and indeed, almost none at all, that gives us an estimate of the percentage of the population that will eventually contract the novel coronavirus. Nevertheless, since this is a new disease and there’s currently no vaccine and no reported immunity from previous infections, an estimated educated guess would indicate that everyone is susceptible to Sars Cov 2 infection!
Researchers from Harvard, predicted in their publication in Nature Medicine this month that globally, “at least one-quarter to one-half of the population will very likely become infected, if drastic control or preventive measures are not enforced, or a vaccine is not developed.
A disease modelling analyses released earlier this month from Imperial College of London has also predicted a situation in which more than 80 percent of the U.S. population could get infected over the next few months, if preventive actions like frequent washing of hands with soap under running water and social distancing were not enforced.
With this scary statistics emanating from the new coronavirus infection, one cannot overemphasize the degree to which the world would have to be disciplined enough to curtail the spread of the virus. Indeed, a scan of the various countries in Europe particularly Italy, Spain, Germany, and France, and the aggressive protocols they have instituted to face this pandemic, give us a glimmer of hope. We are nevertheless faced with an evolving viral infection and pandemic, and the earlier we institute preventive measures to curtail the spread, the better it would be for the entire globe.
Politicians, policy makers, health authorities, and even lay people, have been giving us two messages of late: once you have the virus there are no drugs that can kill it or help you get rid of it. But also, wash your hands to stop the virus spreading.
This seems interesting, especially when even with several millions of dollars available in the advanced countries, we still don’t have a drug for the novel coronavirus, Sars Cov 2 – instead, our ordinary bar of soap kills the virus (it is worth noting here that the antibacterial soaps, so clearly labelled, on the shelves in the supermarket cannot annihilate the virus). So why does soap work so well on this novel coronavirus? The answer is simple – because the virus can be seen as nanoparticle encapsulated by a weak lipid bilayer shell, that is amenable to disruption.
Soap dissolves the fatty bilayer, and the virus either disintegrates and “dies,” or is rendered inactive. Alcohol-containing liquids or gels may have a similar effect but not as effective as regular soap. Apart from alcohol and soap, antibacterial agents cannot effectively disintegrate the virus structure, and hence, may not serve the intended purpose. Soap is the best, but alcohol-containing wipes may come in handy when disinfecting surfaces at home or in the offices.
Nanochemistry of soap
The effectiveness of soap can be explained from our understanding of virology and nanostructures. I will try and explain these concepts without a lot of technical words as applied to my expertise in molecular virology and nanotechnology. I will also try to make it vivid, but as brief as possible. Since too much brevity may also compromise understanding, the writing has been a bit ‘liberal’ in some paragraphs including some details which are deemed vital for general understanding, and not memorization.
Viruses have been (and still are) very fascinating to me in all my thirty years as a researcher in virology, molecular biology and nanotechnology, as I still consider them as classic examples of how nanochemistry and biological weapons intersect.
Coronaviruses consist of three key building blocks: lipids, proteins and ribonucleic acid (RNA). The lipids form a shield or envelope around the assembled virus, and are used for both protection and inter-cellular invasion. The proteins assist with viral replication and permeation into adjoining cells. The proteins also confer supramolecular integrity to the virus structure. The RNA is the viral genetic material (similar to DNA).
The entire virus structure is however assembled on weak interactions between the lipids, proteins and the RNA. They act together as inter-locking entities making it hard to dis-assemble the already self-assembled viral particle. Even then, soap can perform magic in disintegrating and annihilating the viruses!
At the nanotechnology level, most coronaviruses are between 50-200 nanometers – so they can be considered as nanoparticles. The interesting thing about nanoparticles is the varying complex interactions they have with surfaces they are attached to. The same applies to viruses. Metals, porcelain, wood, fabric, and human skin all have affinity and complex interactions with viruses.
When a coronavirus invades a cell, the RNA (genetic material) “hijacks” the host cell’s reproductive machinery like a Trojan horse, and forces the host cell to make several copies of the viral RNA and all other protein components that will constitute a full-fledged virus. These new RNA and protein molecules then self-assemble with lipids to form new copies of the invading virus.
Simply put, the virus does not necessarily replicate its structure by itself; it rather makes several copies of the necessary components or building blocks, which later self-assemble into new viruses, and this can be millions of copies of viruses!
These new viruses eventually overwhelm the cell, and the cell annihilates or dies releasing several copies of viruses that then go on to infect more cells. For respiratory viruses like flu and Sars Cov 2, the viruses generally end up in the airways or mucous membranes of the lungs. When you get infected with such viruses and you cough or sneeze, tiny droplets from the airways can travel to different distances depending on the size of the droplets. The larger ones, mainly carriers of coronaviruses, can travel as far as 6 feet, and the smaller droplets, as far as 30 feet. It goes without saying, that to prevent spread from these droplets, we need to cover our mouths during coughs and sneezes!
Skin: an ideal bed for the novel coronavirus
The tiny droplets from the coughs and sneezes of infected individuals settle on surfaces and dry out quickly. The viruses are, however, still active. What happens next is all about how the nanoparticles (viruses) interact with their environment. Since similar molecules appear to interact more strongly with each other than dissimilar ones, skin, fabric, wood, interact fairly strongly with viruses.
In contrast, metals, stainless steel, porcelain and some plastics, don’t interact that strongly with coronaviruses. The surface structure, which has everything to do with the chemistry and chemical bonds of the atoms matters. The coronavirus will “stick” less to flatter surfaces, as opposed to rougher surfaces
The coronavirus is naturally held together by a combination of hydrogen and hydrophilic bonds. The surface of wood, fibers (organic), for instance, forms a lot of hydrogen bonds with the virus. In contrast, metal, stainless steel, porcelain do not form much hydrogen bonds with the virus.
Consequently, the virus remains stable but is not strongly bound to those surfaces. How long the coronavirus stays active depends on how favourable the surface is. The novel coronavirus is reported to stay active on favourable surfaces for hours to several days. The virus gets less stable in sunlight (UV light), moisture (dissolution), and heat (supramolecular and thermodynamic molecular motions).
With the aforementioned, the skin is an ideal surface for the coronavirus. The skin is organic, and all other cells and dead cells on the surface interact with the virus through both hydrogen and hydrophilic interactions. So when you touch a steel surface that has been contaminated with the novel coronavirus, it sticks to the cells in the skin, and then transferred to your hands.
In this state, you are not yet infected until you touch your face, when the virus can then get transferred. When the coronavirus is within the vicinity of the airways (nose) and the mucus membranes around your mouth and eyes, the virus can get in and get you infected. And since there is no reported immunity from those previously infected with the novel coronavirus, infection is inevitable.
How many times does one touch his or her face? It is reported that majority of people touch their faces every two to five minutes. This could be reflex, and more. So unless you wash off the active virus from your hands frequently, especially as you move around and touch surfaces subconsciously, you’re at high risk of being virus laden. If the virus is on your hands, after you pick it from a contaminated surface, you can easily pass it on by shaking someone else’s hands.
Contacts like hugging and kissing can also transfer the virus. If someone coughs or sneezes in your face, you are likely to get the virus on your skin. So frequent sanitizing or washing of hands with soap should be a culture in these trying times. Washing with water “alone” is not enough, since it cannot outcompete the strong interactions between the skin and the coronavirus via the hydrogen bonds. The virus lodges very tenaciously on the skin and may not dislodge.
Soap – the antagonist to the coronavirus structure
Soap belongs to a group of compounds called “amphiphiles.” These are fat-like molecules that have a dual nature. One end of the molecule is attracted to water and repelled by fats while the other end is attracted to fats and is repelled by water. It’s this dual-nature, considered as a double-edged sword that makes soap very effective as antivirals. The soap molecules compete with the lipids and other non-covalent bonds which help the lipids, proteins and RNA to stick together. In this way, the soap is effectively “disintegrating the adhesive molecules that bind the virus together”
The fascinating power of the soap is its ability to outcompete the bonding between the virus and the skin surface when in contact. Soon the virus gets detached due to the combined action of the soap and water. With lots of running water added, the virus is gone! Note that because the skin has an undulating surface, one needs a reasonable amount of rubbing and soaking in the hands to ensure the soap reaches every nook and cranny that could be hiding active viruses. It is recommended that you rub your hands with soap under running water for at least 20 seconds (twice the Happy Birthday To You Song).
Alcohol-based products typically containing 60 -70 percent ethanol, sometimes with a bit of isopropanol, water and a bit of soap will perform the magic. Ethanol and other types of alcohol are more lipophilic than water, and can dissolve the lipid membrane and also disrupt other nano and super molecular interactions in the virus.
However, you need average concentrations of 60 percent or more of the alcohol to dissolve the virus. Hard liquor like “akpeteshie” which contains about 40 percent alcohol will not work well, unless there could be a double-distillation to increase the alcohol percentage to 60 percent or more, and even with this, you need a reliable method to accurately measure the concentration.
Vodka or whiskey usually contains about 40 percent ethanol and hence, won’t dissolve the virus as quickly. It must be emphasized that, overall, alcohol is not as effective as soap at dislodging viruses. Antibacterial agents (which are strictly antibacterial) will do basically nothing to the virus, unless the products contain alcohol and some soap.
In summary, coronaviruses can stay active for many hours in the air, and on surfaces and then get picked up by touch. They then get to our faces and infect us because most of us touch our faces reflexly and frequently.
Water alone is not effective in washing the virus off our hands. Alcohol-based products work better. But nothing works as best as soap — the virus dislodges from the skin and disintegrates readily in soapy water. Nanochemistry and virology have not only taught us a lot about how the virus self-assembles into a potent biological weapon, but also how we can render the novel coronaviruses ineffective with simple and common household items as soap.
Professor in Virology, Molecular Medicine and Nanotechnology at Regent University College of Science and Technology, Accra