The battle between viruses and their hosts has waged for millions of years. In fact, viruses, such as the influenza virus, are believed to have coevolved with the human immune system. While viruses developed increasingly sophisticated mechanisms to block the human immune system, our immune system developed ways to fight back. In recent years, the advancements of modern medical sciences have learned from the years of conflict to provide our immune system with boosts that gave us the upper hand in the fight against viruses.
But modern medicine relies on historical behavioural data that viruses exhibit against our immune system to make these breakthroughs. Which means we are only as strong as the infections we’ve endured. And every once in a while, we stumble upon a new kind of virus that crosses over to humans from an animal reservoir – a zoonotic virus – leaving our immune system powerless against them. Viruses like these have been the cause of some of the deadliest pandemics and epidemics known to us. The AIDS pandemic that started in the 1980s was caused by the human immune-deficiency virus (HIV) that crossed over from chimpanzees to humans. Similarly, the Severe Acute Respiratory Syndrome (SARS) outbreak in 2002 was traced back to civet cats, and the virus that caused Middle East Respiratory Syndrome (MERS) outbreak of 2012 was transmitted from camels.
But no modern pandemic has had an impact that is quite comparable to the ongoing COVID-19 pandemic. Widespread travel restrictions, nationwide lockdowns, and economic breakdowns; the COVID-19 pandemic has changed the world as we know it.
The virus that causes COVID-19 belongs to the “coronavirus” subfamily of viruses. And this is not the first time that humans have come face to face with coronavirus. The SARS outbreak in China and the MERS outbreak in Saudi Arabia were both caused by coronavirus. There are at least 4 other types of coronavirus that are known to infect humans, causing mild flu-like symptoms.
The coronavirus is a single-strand, covered virus that has protein spikes on its surface giving it a crown-like appearance. In fact, that is where it gets its name (“corona” translates to “crown” in Spanish). Coronavirus, like all other viruses, is incapable of replicating itself outside of a host cell. Inside the virus, lies a single strand of genetic material (RNA) that carries the information to make more replicas of the virus. Once it is inside the host body, the virus makes its way to the spleen, intestines, or lungs. The primary targets of the virus are the epithelial cells that form the lining on organs and mucous membranes.
As it comes in contact with the cells, the protein spikes get to work. The spikes act in a lock-and-key mechanism to insert itself on the cells’ receptor molecules. This allows the virus to inject its genetic material into the cell that instructs the cell to create replicas of the virus within the cell membrane. Once the cell has produced enough viral material, the cell membrane gives away, destroying the cell and releasing a new batch of coronavirus inside the body. And the process repeats itself, with the number of infected cells growing exponentially.
Over time, the growing number of affected cells can, by themselves, pose severe issues to our health. But the process is sped up by the very thing that is meant to protect us: our immune system. The immune system is comprised of various types of cells. One such cell is the immune cell. These cells are responsible for controlling the killer cells like neutrophils and cytotoxic T cells by transmitting information through proteins called cytokines. Upon being infected by the coronavirus, the immune cells relay mass destruction orders to the destructive cells and end up destroying as many infected cells as healthy. This causes permanent tissue damage and, in a vital organ like the lungs, it could lead to life threatening conditions and even death.
The severe effect that SARS-CoV-2 has led national and international health authorities like WHO to issue guidelines on the best practices to prevent the rapid spread of the virus. These include washing hands with soap for 20 seconds and using alcohol-based hand sanitizers to eliminate the virus. However, a lesser discussed, proven method to counter the virus is molecular iodine.
The effectiveness of molecular iodine has been tested against another member of the coronavirus family – SARS. During these tests, it was observed that an exposure of five minutes eliminated all infectivity of the virus. And recently, Philippines, Thailand, and Vietnam have been using Povidone-iodine as an active agent to fight COVID-19 cases.
The mechanism that molecular iodine uses to destroy the virus differs from that of soap and alcohol (60%-80% ethanol). While soap and water use amphiphile molecules to break open the hydrophobic membrane of the virus, alcohol-based hand sanitizers weaken the intermolecular bond between the membrane molecules to destabilize the virus. Both methods can effectively eliminate any viral load that may be present on the skin.
Iodine-based disinfectants, on the other hand, relies on a different mechanism to inactivate the virus. In contrast to soap and alcohol, the antiviral activity of iodine-based disinfectants is caused by free molecular iodine (I2). Iodine has excellent penetration abilities and low reactivity with protein material. When applied to the skin, iodine-based disinfectants release free molecular iodine which penetrates the skin’s epidermis and forms a solid solution. This prevents it from being washed away or reduced. However, the iodine load inside the skin does decrease over a long period of time. This is because the iodine diffuses back onto the surface of the skin in the form of a colourless, odourless gas, forming a gaseous antiviral shield on the skin.
It is in this form that the molecular iodine begins the inactivation of the virus. The extremely slow release of iodine also ensures that it provides protection against the virus for extended periods of time, decidedly longer than the 5-minute barrier for complete loss infectivity of the virus.
There is no “one” correct way to fight the COVID-19 pandemic. But free molecular iodine provides users with a longer protection than its soap and alcohol counterparts. As we keep making our way through the pandemic, there can never be enough tools to protect us. Iodine-based disinfectants are just another addition to the arsenal in our fight against this faceless enemy.