It is becoming clear that, whilst checking for the usual suspects in effective immune defence against Sars-Cov-2 viral infection includes IgG and IgA and IgM, other mechanisms embedded in our innate and adaptive immune systems may also be at work protecting you.
Pre-infection, there already exists a range of defence strategies your immune system holds ready to deploy, and as has been discussed and explored to date (in prior e-news), it seems that not everyone exposed contracts the virus at a level that induces symptoms, or indeed even contracts the virus at all. Viral load, length of exposure, indoor/outdoor and existing state of health and immune competence all intersect to provide a ‘shield’ of resistance/resilience.
In some people, this is enough to prevent symptoms and illness. Within a week or two of exposure a more “adaptive” response then emerges: your body may produce bespoke antibodies, which bind specifically to the virus, and specialised T-cells, which remove cells that have already been infected. It also seems that prior infection with ‘coronavirus’ species of some sort can confer cross reactive adaptive T cell mediated immunity against SARS-Cov-2. Some studies have already shown a cross-reactivity, but others show none. Differences in these results may be down to how immune responses were analysed, or variations between people’s immune responses who could have had different prior exposures. Either way, such conflicting observations highlight the complexities involved.
Prior exposure to another coronavirus is one reason that a large chunk of the population may be able to deal with the virus as they have some small residual immunity from exposure to common cold viruses. A key part of your immune system, T cells can recognise fragments of viruses. When the cells identify a viral protein, helper T cells release chemical signals that trigger other parts of your immune system to kick into gear. Others, called killer T cells, hunt down and kill infected cells.
There are two primary takeaways from these observations.
The first is that vaccine development (a process being perused internationally) will have at least two adaptive responses to target for developing long term immunity – the B and T cells. These cells work together to orchestrate a targeted immune response. But the way they recognise and deal with germs is different.
Both T cells and B cells have an important receptor molecule on their surface, not so imaginatively called the T cell receptor and the B cell receptor. B cell receptors lock onto unique structural components of a germ, or an infected cell, directly. T cells, on the other hand, need other immune cells to chew up and present parts of the germ in small fragments, which can then be scrutinised. The effect is to encourage a response that confers a hastened capacity to defeat future SARS-Cov-2 exposure.
Yet vaccine development is by all accounts a long and challenging road and vaccines of course are themselves not without application risk. A little-known phenomenon called antibody-dependent enhancement (ADE), also known as disease enhancement or immune enhancement is one. This occurs when the presence of antibodies, which are supposed to vanquish disease, worsen rather than quell an infection. If this factor alone were to appear with the developing ‘183 by June 10’ vaccine proposals there would be a serious risk involved in being vaccinated and likley a significant level of resistance to being vaccinated. A similar problem has occurred with the vaccine Dengvaxia and should give all vaccine developers cause for caution – despite the intensive pressure they are all under.
We all know that food has a direct impact on the human condition and immune function. A diet low in essential nutrients will produce a different immune competence to one in which healthy food is consumed along with appropriate food supplements. Yet the journey to healthy food and eating starts long before the meal. It begins with the soil. The multitudes of organisms in this sub-surface wonder world transfer the nutrients embedded in the soil to the plant. The more organisms, the more the nutrients are transferred to the plant. The higher the nutrient uptake by the plant, the healthier the plant and the more nutrients are deposited in either the crop, the fruit, the grass, or whatever is being produced for human or animal consumption.
The journey is not over yet; it becomes even more exciting. It moves from the bacteria and organisms in the soil that nurture the plant, to the bacteria and organisms in the human gut that, as the first line of defence in our immune systems, nurture our health.
From soil health to food health, to eating and drinking, to human health and immunity, but how to start this process? It starts with people caring for others, caring for nature, caring for the soil, and applying management practises that regenerate life. It is quite simple really: when the farm is managed in a way that revitalises soil life, then that life will be transmitted to the plant and to the food, and to us.
Heal the land, heal the people. This is more than a catchy phrase. It is our life. It is our future. While the land and we are being healed through regenerative processes, the resilience and robustness of the social-ecological ecosystem is strengthened. The social-ecological ecosystem is the interaction between people and nature, and among people and nature-based organisms that make life possible and healthful.
Our food choice translates via multiple pathways to provide access for our cellular generation of suitable and proportional immune responses. T cells and B cells as well as all components of your immunity need nutrients to develop and function, nutrient deprivation in our soils means also compressed immune tolerance and the increased risk of an over responsive immune event.
Simply put: the more the diversity in the soil, the more the diversity is in the human digestive system, the better our collective capability to withstand diseases and environmental catastrophes. Ecological, social and financial risks, be that a virus of any kind, malnutrition or climate change, are therefore tempered.
We have a responsibility to nurture our soil’s health as well as our own psychological and physical health. Perhaps post Covid-19 there will be a louder voice recognising that fixing things up stream in the delicate membrane that covers our planet and on which all life depends is a cheaper way than fixing future pandemics and chronic disease, rather than at the exposure end?
Soil is the basis of fibre and food systems, climate change and stability, and our futures are rooted in restoring and strengthening our relationships with each other and with the soil ecosystem. By starting with carefully selecting the food we consume, we can invest in systems that we want to support and that revitalise our environment.
A WWF report, published on 17th June 2020, also warns: “The risk of a new wildlife-to-human disease emerging in the future is higher than ever, with the potential to wreak havoc on health, economies and global security. The interdynamic relationship between you and the environment is hopefully becoming clearer in a way that makes for considerate change in future government and public health policy.
On a final note, as the UK government organise a Public Health Officials review (also announced on June 17th ) into the potential role of Vitamin D in the prevention of Covid-19, Dr. Adrian Martineau, a professor of respiratory infection and immunity at Queen Mary University of London says: “Vitamin D could almost be thought of as a designer drug for helping the body to handle viral respiratory infections,” he said. “It boosts the ability of cells to kill and resist viruses and simultaneously dampens down harmful inflammation, which is one of the big problems with Covid.” It’s a start!