BIRD FLU: A BAD PLAN
Yesterday, RFK Jr. said that instead of culling birds when the infection is discovered, farmers “should consider maybe the possibility of letting it run through the flock so that we can identify the birds, and preserve the birds, that are immune to it.”
This is not only a bad idea, but it also reflects the problem of having a politician leading a scientific agency, without the education or, apparently without good advisors.
Let’s look at why this idea is not only bad, but scientifically wrong.
Bacteria mutate during reproduction, and sometimes those mutations allow the new emerging strain of bacteria to be resistant to antibiotics. This is a form of natural selection and evolution, and it occurs because of the huge numbers of bacteria and a high rate of mutation and the ability to modify the genetic code of the bacteria to create a new strain with the same resistance.
In animals, evolution has resulted in some animals developing resistance to toxins. For example, the mongoose can prey on cobras because they have evolved to be resistant to the cobra’s toxin. Similarly, the grasshopper mouse can resist the toxins in bark scorpions and prey on them, and cobras can resist their own toxins. This is also a change in the genetic codes of those animals that can lead to a new strain with that resistance.
However, these types of resistance have developed over centuries. If you put a hundred thousand non-resistant animals in a box with venomous snakes, a hundred thousand will die. The types of mutations that allow resistance are extremely rare, and the emergence of a resistant new animal type is even more rare.
Bird Flu is fatal to at least 90% of infected chickens. Letting it run wild in a flock without culling infected birds will result in a death rate of 90%. Culling the flock when infected chickens are detected can preserve the bulk of the flock.
Putting a fence around the flock will not protect them as Bird Flu is spread by birds who fly around the country.
So, why isn’t the virus 100% fatal? Because some of the birds have resistance to the virus. For this discussion, let’s look at what the Secretary focused on – immunity. Let’s assume that the 10% of the chickens in the flock that survive infection do so because they have some natural immunity to the virus. Mr. Kennedy then concludes that if we then save those chickens who had immunity to the virus, that their offspring would inherit that same resistance.
THIS IS TOTALLY INACCURATE.
I have written in the past about how the immune system works, but it may be useful here to recapitulate that explanation.
We DO NOT inherit the immunity of our parents.
Sometimes, we confuse things; and that is understandable. For example, we have been taught that mother’s milk is important for the health of the newborns, because the mother’s milk contains antibodies that protect the newborn. This is not because the mother transfers her immune system to the baby, it is simply because those antibodies within the mother can “passively” protect the baby. That protection does not last longer than the time in which those antibodies pass through the baby’s system. There is no permanent protection. It is like drinking a cup of coffee; the effects of caffein appear shortly thereafter, but as the molecules are metabolized, those effects disappear. Drinking coffee does not confer “caffeination” permanently.
We also inherit many things from our parents, like hair color, eye color, risks of cancer and other diseases, and many mannerisms. Those inherited traits come directly from the genetic material that we inherit.
But this is not the same for immunity. We don’t inherit the immunity conferred upon our parents by vaccination. Just because our parents were immunized against polio, we need to be vaccinated ourselves. We do not inherit hay fever or other allergies from our parents, the allergies that they have are not transferred to us, we develop them ourselves.
Why is this?
To understand this, you need to understand “GOD”, the scientific acronym for “Generation of Diversity”, or “how does your immune system recognize foreign substances and rise to fight them?”
The immune system in your body constantly creates new antibodies (for the purpose of this discussion I will speak about antibodies, but the same description applies to B-Cells and cellular immunity – T-Cells).
The tips of the antibody molecules contain sticky pieces that can attach to other things. When antibody producing cells are formed, they randomly vary those tips, so that the ability to attach to other things changes. That randomness is critically important, because the system that creates those new cells is incapable of “learning”. It DOES NOT “see” a foreign substance and then build an antibody to attach to it. This is probably the most important thing for you to understand. It is the RANDOM development of a library of antibodies that provides the resources of the body to recognize something foreign. When the body is challenged with a foreign substance like a virus, and IF there are antibodies that coincidently can attach to those viruses, the cells that produce that antibody will be stimulated to expand and make more of those antibodies. Each cell only makes ONE antibody, so any cells that have antibodies that can attach to that virus will be stimulated to divide and grow. This is what we refer to as “an immune response”. In most cases in humans, there are lots of cells whose antibodies can attach “recognize” different parts of that virus. Some bind really strongly, some bind weakly. With a sufficient group of antibodies, the body can fight off the infection. Now, it does take some time for those cells to be stimulated and to divide and expand, producing a sufficient immune response to kill the virus. This is usually about 7-10 days, and that is why most infections last that long. Once you have recovered, you maintain the ability to quickly respond to that same virus for a long time.
But remember that the ability to resist the disease was developed by a RANDOM creation of antibodies. These antibodies WERE NOT coded in the genetic material of the individual, they were created AFTER birth. So, those antibodies can NEVER be inherited. Not, inherited sometimes – NEVER. Each individual develops their own, unique library of antibodies. Some people will not have antibodies that can react to the viruses, some will, most will be different, one from another.
When you are vaccinated, scientists have developed a model of the virus to stimulate that immune response without causing the effects of the disease. But that response is identical to if you had been infected with the virus, the ability to respond to the vaccine is based on the random recognitions of your own antibody library. That is why vaccine-conferred immunity cannot be inherited.
Chickens have a similar immune system, but it is significantly weaker (they don’t make as large a library as humans do).
If you now understand how immunity works, you can see the foolishness of the Secretary’s suggestion. The few chickens that may survive a Bird Flu infection because of a quirk in their generated immune library, CANNOT pass that immunity, or the ability to develop it, on to their offspring. 90% of a flock grown from the surviving chickens will still die from the disease.
More importantly, if we allow the infection to spread, uncontrolled among chickens, we will be creating a larger reservoir for the virus to grow and to mutate. The larger the reservoir, the larger the number of viruses, and the larger the number of viruses, the more mutations that will occur in that virus (most viruses have specific, defined rate of mutation, so the more viruses, the more mutants), and the more mutants, the higher likelihood of creating a new strain of virus that can infect humans and allow for human-human transmission.
The idea of allowing Bird Flu to run, unchecked in flocks WILL NOT provide virus resistant chickens, and will accelerate the risk of becoming a human virus.