What is the common cold?
The common cold is by far the most prevalent disease worldwide. In fact, in 2019, it was estimated that there were around 17 billion colds each year worldwide[1], easily dwarfing the next most prevalent illness, which was diarrheal diseases (7 billion cases), and in third place was HIV/AIDS (2 billion cases). Diseases 2 and 3 are most prevalent in third-world countries, but the common cold is a huge problem in the developed world.
Every adult can expect to suffer through 2-3 colds a year, and children can expect up to 10 colds yearly. Although colds are generally mild and resolve by themselves within 7-10 days, the sheer number of cases each year means that the illness causes enormous overall suffering and high economic costs due to lost workdays and school days. Colds can also lead to secondary bronchial infections that can extend the illness period, and in vulnerable people, like asthmatics and the elderly, can lead to serious complications and hospitalization in some cases.
Viruses cause colds
Almost all colds are caused by viruses, although in a small percentage of cases, bacteria can also be involved. The most common viral cause is the ‘rhinovirus’, which accounts for around 50% of adult colds and up to 80% in children.
| Virus | % of colds in adults |
|---|
| 1 | Rhinoviruses | 50% |
|---|
| 2 | Coronaviruses | 20-30% |
|---|
| 3 | Influenza virus | 5-10% |
|---|
| 4 | RSV | 2-5% |
|---|
| 5 | Parainfluenza virus | 2-5% |
|---|
| 6 | Metapneumovirus (HMPV) | 0-2% |
|---|
People are often surprised to learn that coronaviruses are the second most common cause of colds. These are coronavirus strains that have been around for decades; they may have started as more serious illnesses but quickly evolved to become part of the mix of seasonal cold viruses.
The coronavirus family has recently been joined by SARS-CoV-2 (the virus that causes COVID-19), which as we all know has now evolved to a low virulence, highly transmissible virus that causes cold-like symptoms. Because colds are defined by the symptom complex, not the causal virus, we can say that SARS-CoV-2 is now a cause of the common cold!
The quest begins
Decades of research were invested into finding a way to beat the viruses that cause colds, and for a while, there was great optimism that we would win the war. However, there are more than 100 variants of rhinovirus alone, and hundreds of strains of other viruses, making it impossible to develop a vaccine for the disease. We all saw how quickly the SARS-CoV-2 virus became resistant to the COVID vaccines. Imagine that across the board for all cold viruses.
Initially, many researchers thought antivirals could be the answer, in the same way that antibiotics beat most infections caused by bacteria, but respiratory viruses are promiscuous bugs that can rapidly evolve to find a way around a targeted antiviral agent.
In the absence of any effective treatment for colds, and often under pressure from patients for ‘something!’ some doctors prescribed antibiotics to fight colds. Sadly, as we explained in anotherarticle, antibiotics are not at all effective against viruses and their widespread use against viral infections has contributed to the global problem of antibiotic resistance.
The ultimate goal in common cold research was abroad-spectrum antiviral that would kill all viruseswithout any potential for resistance. However, despite some promising early research, the grand prize of antivirals was never found.
Recently that changed, as we will explain below.
Covid changed everything
Soon after COVID-19 appeared, it was clear to many scientists that, like other respiratory illnesses, the leading site of initial infection by the virus was in the nose. We breathe the virus in mostly from airborne microdroplets that settle in the nasal passages. The virus infects some cells and starts replicating inside those cells. In the case of the COVID-19 virus, it usually causes only mild or no symptoms in the nose; however, once it’s released from infected cells, it can be breathed into the lungs, where it can cause the life-threatening illness we associate with COVID-19.
So scientists started working on nasal sprays to eliminate the virus in the nose before it could do harm. The two most promising approaches were nasal sprays containing povidone-iodine (PVP-I) and nitric oxide (NO). Both are broad-spectrum antimicrobials that kill all viruses. Both had good safety profiles in nasal use and initial trials showed they both reduced the SARS-CoV-2 ‘viral load’ (amount of virus) in the nose. Both are commercially available as nasal sprays: the main NO product is calledNOWONDER™(previously Enovid) and the PVP-I product that has been most widely tested is calledNasodine®.
Okay, so what? COVID-19 is in the rearview now, right?
Nasal sprays for colds and flu
If a nasal spray is safe to use, kills all viruses and reduces viral load in the nose (as evidenced by the COVID-19 studies), it could surely be useful as a treatment or preventative for the common cold and other respiratory viral or bacterial illnesses. The answer is yes, at least for PVP-I.
In 2020 and 2021, several companies jumped on the COVID wagon with PVP-I or NO nasal sprays in response to the pandemic. Naturally, they also saw a commercial opportunity in offering consumers protection from the virus.
Meanwhile, an Australian biotech company had been working on a PVP-I nasal since 2012. They called the company “Firebrick” Pharma because the Google color ‘Firebrick’ is a deep, rich shade of red, just like PVP-I powder. Firebrick’s goal was a PVP-I nasal spray that could finally be the grand prize, an effective treatment and preventative for the common cold. They called the product Nasodine®Nasal Spray.
It took seven years of R&D to develop a high-quality nasal spray that was safe, convenient to use, and stable for at least two years on the shelf. They also completed phase 1, 2, and 3 clinical trials to prove its safety and efficacy in people with the common cold. Guess what? They achieved all this by the end of 2019, just before COVID-19 came along.
Of course, once COVID-19 hit, no one was very interested in the common cold. However, the world has turned. Now, people are much more aware and sensitive about the risks of viral transmission. Enter Nasodine®.
In a post-COVID world, a PVP-I nasal spray that kills all respiratory viruses, is proven safe, is effective, not only for COVID but as a treatment for the common cold, is a winner.
How it works
First, it’s important to know that PVP-I doesn’t get inside cells. It works as a topical antiseptic or nasal ‘sanitizer’ that kills viruses sitting outside cells and lurking in the nasal mucus. So it can’t touch the virus once it has infected one of your nasal cells and starts replicating inside that cell. But soon enough, infected nasal cells burst open, releasing hundreds of new virus copies that can infect other cells in the nose or lungs, and can infect other people. That’s when PVP-I kicks in.
According to the Firebrick patent, when you get the first signs of a cold, your nasal cells are already infected, so taking immediate action is important. It’s also important to apply the product regularly to the nasal passages, especially on the first day. This helps wipe out most of the viruses, i.e., shrink the nasal viral load, and interrupt the infection cycle.
Shrinking the nasal viral load should also reduce the risk of transmission of the virus to others. Whenever you blow your nose, cough or sneeze, viruses are carried by airborne droplets that can be breathed in by others. By shrinking the number of viruses in your nose, you could expect to increase the chance that those droplets are non-infectious.
Beat the virus before it causes trouble
Rather than wait until you get infected, the patent also suggests that the PVP-I nasal spray can be used preventively, to kill the virus in the nose before it gets a foothold. In some countries where it is commercially available (e.g., Singapore: nasodine-sg.com), it is actively promoted as a preventative to be used whenever people around you have symptoms and expose you to viruses.
This includes use when you are in crowds, commuting, airline travel, and when the children come home with one of their never-ending colds. Airline travel is a no-brainer because we can’t control who sits next to us. Indeed, one article[2]stated that if someone near you on a plane has a cold, you have an 80% chance of catching it!
Better to use Nasodine®.
[1] Jin, X. et al. (2021) “Global burden of upper respiratory infections in 204 countries and territories, from 1990 to 2019” eClinicalMedicine, Volume 37, 100986
[2]https://www.*.com/getting-sick-on-an-airplane-flight-2018-3
(20min delay)