- EURASIAREVIEW.COM - A la une - Hier 23:43

Defunding Gavi: An Important Step Toward Decolonization? – OpEd

The primary reason people in wealthy countries live longer than those in poorer countries is that they have better sanitation (e.g. clean water, hygiene), nutrition (especially fresh food), living conditions (e.g. housing), and access to basic healthcare – like antibiotics for childhood pneumonia. This should be uncontroversial – it was taught in medical schools a few decades ago when evidence formed the basis of medicine. The fact that it is now widely forgotten, or ignored as a matter of convenience, explains why there is such a fuss over the United States administration defunding Gavi – the ‘Vaccine Alliance’ based in Switzerland. Our Age-Old Argument with Pathogens As most public health people seem unaware, and many of the public also, let us review why so many of us now reach old age. Humans are constantly exposed to microbes that could cause harm. The vast majority don’t, as our forebears spent hundreds of millions of years evolving defenses against them, even as the microbes evolved new ways to use our bodies to multiply their own. Mostly, we live in harmony with bacteria – our gut is full of them, but they also cohabit in our bloodstream and elsewhere – even possibly in our brain, as that is demonstrated in other vertebrates. Most of the cells we lug around are actually not us, but bacteria that live with us. Some microbes (bacteria, viruses, fungi, protozoa) and even small worms of various sorts can, however, cause us great harm (they become pathogens). Their genetic code is, like ours, designed to reproduce itself, and to do this they need to eat part of us or hijack the metabolism of our cells. In doing so, they can sicken or kill us. We have evolved very effective ways to prevent this, by developing skin and mucosal barriers that hamper them from entering our bodies, and producing cells that eat or otherwise destroy them (our immune system). The brilliance of our immune system is that it has a memory. Once it has developed an effective chemical or cellular response to a pathogen, it stores that code so that an effective response can be very rapidly reactivated if the same pathogen comes along in the future. Some pathogens frequently change their chemistry to try to get around this and still reproduce within us, and our immune response has to keep adjusting. The Growth of Human Resilience So, back to sanitation, nutrition, and living conditions. Relatively recently, we figured out what pathogens are (bacteria, viruses, protozoa, nematode worms, and the like) and better understood how to avoid them altogether. Many of the pathogens that used to kill us spread from person to person through a ‘fecal-oral’ route, as it is euphemistically called. They reproduce within the body, and the resulting multitude move on when we defecate. If someone then drinks water contaminated by that, they get infected. Cholera, typhoid, and E. coli are well-known examples. Beyond aesthetics, this is why we have sewerage systems in towns and cities. We stopped most deaths from these simply by drinking clean water untainted by someone else’s toilet. Pathogens that spread by respiratory routes to cause disease (e.g. influenza, Covid-19) are more likely to pass between people if they live in a confined space with poor air circulation. This raises the chance of breathing in air others have breathed out, and increases the number of organisms that infect us at once (i.e. infective dose or ‘viral load’). A high infective dose makes it more likely that we get very sick before our immune system can mount an effective response. Good nutrition is absolutely essential for us to mount an effective immune response, whether to an organism or a vaccine. The cells in the immune system have specific requirements, such as Vitamins D, K2, C, and E, and zinc and magnesium, and cannot function well without an adequate concentration of them. They can also be impaired in their function when our general metabolism is impaired, such as in diabetes, starvation, or chronic diseases and anemia. As we have improved access to fresh and varied food over the past two centuries, we have allowed our immune systems to function more optimally. We may still get infected, but we nearly always win the human-pathogen battle. Over the past few hundred thousand years or so, our ancestors also developed a compendium of plants that, if eaten, helped rid us of the sicknesses that microbes cause. In the past hundred years, our increasing knowledge of bacteria in particular has enabled us to understand their metabolism and develop specific antibiotics to slow their growth or kill them (we also have some against viruses and fungi). Antibiotics have helped enormously, but even they are often useless without a functional immune system. This is why people with no immune cells (e.g. due to cancer treatment) have to remain in sterile tents until immune competence returns. We have also developed vaccines – starting with smallpox well over 250 years ago but with most developed only in the past 50 years, well after most early mortality from infectious diseases had gone away in wealthy countries. Vaccines work by tricking the immune system, presenting it with something with very similar chemistry to one of these harmful pathogens so that it develops an immune memory that can be activated if the real pathogen comes along. Providing the vaccine is far less harmful than the pathogen, it is a really clever trick. Gavi and Survival This brings us back to Gavi – the Vaccine Alliance. This public-private partnership was formed in 2001 at a time when biotech (clever stuff that can profitably help reduce sickness and death) was really taking off, and private finance (especially from very wealthy individuals running rapidly expanding software companies) was accordingly becoming interested in public health. Gavi is solely devoted to supporting the distribution and sale of vaccines to low-income countries. These populations have not undergone the full transition to longer lifespans that improved economies brought elsewhere. Much of its funding is public (taxes), while private pharmaceutical interests help direct its work. Its many hundreds of staff have been successful in getting vaccines to more people more cheaply. Mortality was declining pre-Gavi due to improved nutrition, sanitation, living conditions, and access to antibiotics, as low-income economies slowly improved. We can assume this decline would have persisted without the addition of mass vaccination (this much is obvious). Disease incidence would have been higher (more pathogens circulating), but the pathogens were becoming less deadly overall as human resilience improved. What we don’t know is whether mass vaccination, and the work of Gavi within this, made much difference. It really may have, helping accelerate the transition to better survival, or it may not have done much at all. Saving a malnourished child from measles so that they die from pneumonia or malaria is not really a saved life, so comparisons between interventions are difficult to make. This uncertainty was fixed by calling many infections ‘vaccine-preventable diseases.’ Thus, reducing them becomes, in people’s minds, dependent on vaccination rather than improved food, water, and living space. This helps Gavi to claim many millions of lives saved, which is important for donors. While training more health workers, improving access to fresh food, or improving sewers and water quality may save more lives overall, it is really hard to put firm numbers on these. At least you know how many vaccines were dispensed.