Prior to 2020, you could have written what most people knew about the nature of viruses on the back of a postage stamp – the main points being that you can’t treat them with antibiotics, and they make you feel rubbish.
We knew that winter sickness bugs were caused by viruses, and that if one got into our homes, schools or workplaces, we should be careful about washing our hands, and aim to disinfect surfaces – but we didn’t really know why.
Enter a little-known bug by the name of SARS-Cov-2, and our lack of knowledge led to a lot of panic, misinformation and general confusion about what would and would not work to kill a virus.
Would sunlight kill it? What about heat? Does soap and water work, or do you have to use bleach? What about antibacterial sprays and wipes – are they effective? How much alcohol is enough to kill it? The questions went on and on.
As we went on our journey to bring Ramsol to market, we made it our mission to fully understand the answers.
So how do you kill a virus?
Rule number one of warfare: know your enemy. The key to conquering a virus is recognising that it is not the same as a bacterium – it does not behave the same way, and cannot always be killed using the same methods.
What are bacteria and how are they killed?
Bacteria are living, single cell organisms that can move, grow and reproduce on their own. They are large enough to see under a microscope and usually take the form of tiny rods, spheres or spirals. Bacteria can communicate with each other using chemical signals, form communities of sticky biofilm, and evolve their DNA to become resistant to attack from things like antibiotics. Bacteria are found in every location on earth. Good bacteria are essential for the survival of many life forms. Pathogenic bacteria usually cause localised infection, for example in a wound or organ.
Humans have developed many ways to kill bacteria, from antibiotic drugs to antibacterial chemicals. Most work in the same way – by dismantling the proteins that make up the bacteria’s cells. Heat, radiation and chemical compounds can all be used to kill bacteria.
What about viruses?
Viruses are essentially parasites. Each one is called a virion and is so small it can’t be seen with a normal microscope. Virions vary in shape but have a similar structure, with a protein ‘coat’ surrounding their central DNA, and a surface studded with spikes of protein that they use to bind themselves to living cells. The spikes are a bit like a key that fits into a lock on the host cell, and certain viruses will attach better to certain types of cell. For instance, SARS-Cov-2’s spikes allow it to latch particularly well to cells found in the lungs and small intestine.
Some viruses also have a fatty outer layer. These are known as enveloped viruses, and are easier to kill than their tougher, non-enveloped counterparts. Coronaviruses are enveloped viruses.
Once attached to a cell, a virus hijacks that cell’s ability to reproduce and uses it to make millions of copies of itself, which spread rapidly throughout the host’s body, causing a systemic infection.
How the body attacks a virus
Inside the body, our immune system has various tactics for attacking viruses. Special immune cells can identify infected cells and shut down or destroy them, while antibodies stick onto the protein spikes on virions, preventing them from attaching to a host cell. Antibodies work together by binding virions together, making it easier for other immune cells to see them and ‘mop them up’. Antiviral drugs can help to speed this natural process along, but there is still no way to actively kill viral cells inside the body.
What about viruses in the environment?
Outside the body, virions can be destroyed with high temperatures, chemical compounds and radiation, just like bacteria. But not all virions are the same, and what works for one virus may not work for another. This is for two main reasons – virus structure, and infectious dose.
Non-enveloped viruses are more difficult to kill because their tough, protein ‘coat’ is harder to break down. Norovirus, for example, cannot be killed using alcohol-based sanitisers or even soap and water, unless the water is close to boiling. Furthermore, the infectious dose required to cause a norovirus infection is miniscule – the tiniest amount of virus can make a person sick, which means that extremely thorough disinfection is required to prevent its spread.
SARS-Cov-2 is an enveloped virus, which means it can be killed using alcohol, and other disinfectants. But scientists suspect it also has a low infectious dose, which explains why it spreads so easily, even through casual contact. As a result, disinfectants used to kill it (and other viruses) must be tested in terms of how much virus they kill, and how quickly, in order to be proved effective.
Furthermore, environmental factors can inhibit the effectiveness of disinfectants against viruses. Dirt and grease on surfaces can protect the virions against the chemicals that would otherwise kill them. In order to achieve proven virucidal status in the UK, disinfectants must be tested in dirty conditions to prove that they work.
With Ramsol, you don’t have to take our word for it. To request copies of our product’s laboratory test results, email firstname.lastname@example.org