I dreamt last night about a huge ocean liner having to be guided through a river to the port and the only possible way for this to happen was with the assistance of a small tug boat. A tug is a special class of boat without which mega-ships cannot get into a port.
The dream seemed to indicate that although some things look powerful and invincible they also need expert guidance that might not appear powerful but which are absolutely necessary in order for them to achieve their goal.
On contemplation I thought of how the corona-virus seems like a large imposing ocean liner, so invincible and imposing and yet it too requires assistance in order to reach its host.
The new corona-virus is transmitted from one person to another as it is ‘shed’ by an infected person into the environment. The virus must survive that environment before infecting another person, who must either inhale the virus in respiratory droplets or make contact with a virus-contaminated surface. So just like an ocean liner trying to dock, the corona-virus has to survive the external environment in order to reach and infect a new host.
Scientists already know that the new corona-virus survives in droplets in the air and on surfaces. The two main routes of transmission are by breathing in the virus; or by the virus on surfaces being transferred to the eyes, nose and mouth by people’s hands. But it cannot infect the host by itself, it needs our help in order to ‘dock’. This is why currently creating barriers to its movement is so important, barriers such as social isolation, hand washing and avoiding face touching aims to interrupt both. [1]
In elemental terms, air and water assist in transmitting the virus but fire and earth seem to inhibit it. Currently there is no evidence to support that the virus can be transferred between a pregnant woman and a fetus. We know that the body’s first response to the virus is to instigate heat within the body because your body is trying to kill the virus that caused the infection. Most viruses do well when your body is at your normal temperature but if you have a fever, it is harder for them to survive. The problem is though, that none of our senses are aware of its existence until we are infected,which is when our immune system reacts.
Our immune systems therefore are really the key to the virus’s demise and in this regard, immunologists are like the expert tug boat operators steering the path of our fight against the coronavirus.
Renowned immunologist Professor Ian Frazer says that the coronavirus must ‘run its course’, which he thinks will take about a year in Australia. According to Professor Frazer, “this is a fairly infectious virus and I think it would be highly difficult to contain it even with all of the measures that we’re now putting in place in Australia . We have to be realistic, even if the animal testing suggests that this is possibly an effective vaccine, it will take at least a year to get through all necessary steps from having a potential vaccine, working out how to scale up production of it, going to tests for safety in humans and eventually tests in the community to see if it’s effective.
Professor Frazer believes that this is not something to panic about, but something to accept and get on with life and make sure we are ready for whatever happens. The good news is that we can slow the epidemic down with social distancing and hand washing.” [2]
So, if this is the case why are so many people dying from the infection?
According to Dr Larisa Labzin’s, a molecular biologist whose particular area of expertise is the innate immune system – “the innate immune system is the body’s first line of defence against invading organisms, such as viruses and bacteria. That’s where alarm bells first go off that a pathogen is travelling through our bloodstream and targeting our cells, which in the case of the COVID virus are mostly those of the lungs. And it’s been there, in the innate immune system, where the COVID-19 virus has been proving to be such a difficult foe to fathom. Importantly, in the absence of a vaccine, it’s also the place where we have the best chance to fight the disease. [3]
But there seems to be an issue with some people’s immune systems over reacting. The immune system needs to first determine whether it’s a virus that it needs to respond to and then which one, because it has to mount a different response to a seasonal flu virus, for example, than to the COVID virus. “The innate immune system can detect signs without necessarily knowing what is, or has been, there,” Dr Labzin says. “So, I really do think of these cells like they’re police trying to work a profile, picking up various clues as to who the perpetrator might be.”
But what happens in severe cases of COVID-19 is that these cells – these molecular detectives of the innate immune system – aren’t working properly. They detect some part of the COVID-19 virus, or damage to other lung cells caused by the virus, and overreact in an unhelpful way. Then it’s like trying to put out fire with more fire: as those macrophages keep trying to solve the problem with more cytokines, more macrophages come in, try to fight, get it wrong and release more cytokines. The result is a cytokine storm.
“So, when that gets out of control or that signal constantly keeps getting sent, that’s when we start getting a lot of damage and sickness,” Dr Labzin says. “And that’s because these immune cells are pretty powerful and as they go all out to try and kill the virus it often includes taking out some of your own cells as well, which can cause a lot of damage.”
It explains what’s often seen in adults with COVID-19, particularly elderly patients – a very strong hyperinflammatory response. “So, even when tests show virus levels are dropping or very low in a patient’s blood, they can be very sick because the immune response is so high and has kind of stormed out of control, causing really severe damage,” Dr Labzin says.
“This has been confirmed by the success of dexamethasone (an immune suppressant) in treating patients seriously ill with COVID-19. By the time they are hospitalised the damage is being caused by the immune system, not the virus, and we want to understand why that’s happening,” she adds.
So, immunologists, if you guys are the tug boat operators, what sort of tug boat do we need to steer the ship? The ability of doctors to manipulate a patient’s immune response with drugs to prevent this sort of extreme reaction may be vital to prevent death from COVID-19 and is a priority for research.
But in the meantime we each have a responsibility to do what we can to maintain the tug boat, to ensure that our immune systems are ship shape and reacting in an appropriate way!
The Harvard Medical school have some great practical advice that we can follow to building a healthy immune system: https://www.health.harvard.edu/staying-healthy/how-to-boost-your-immune-system
[1] https://coronavirusexplained.ukri.org/en/article/und0002/