Vaccine impossibility theorem
The theme of my previous post is the failure of the vaccine crusaders to understand the nature of public health. Essentially, the crusaders treat the problem as if a one-size fits all solution will lead to positive results, while at the same time neglecting the myriad of side effects, real and potential, that can and have occurred. However, the more important point that I feel needs expansion is the problem with reaching herd immunity through mass vaccination.
This post will take a deeper dive into some of the more nuanced aspects of the topic. Of course, to truly cover the inherent complexities of mass vaccination, we need better data. What data we do have is either too noisy or missing, and thus, we have to concern ourselves with the theoretical aspects of mass vaccination. In reality, we will never truly get to see the data that governments are working with, or have input in the way the data is collected. The reason for that is simple: governments, generally, tell the stories that their biggest stakeholders want them to tell. With the right data, any story can be told. As Frank Herbert might say, “He who controls the data controls the universe”. But that is not an enormous problem because, characteristically, the same conclusion can be reached.
First principles
We need a starting point for our discussion, so I propose some axioms about the current batch of vaccines. These vaccines have distinct features than those that people generally associate with vaccines. They are . . .
Non-sterilizing; and,
Possess a limited duration of action.
Both of these are key features to the vaccination problem, and neither are controversial. Even the most ardent vaccine enthusiast would cede these points. What is controversial, perhaps, is the numerical values that we can attach to each point. For (1), is the VE 20% or 90%? Somewhere in between? You can debate these points endlessly with literature or data points pointing towards all possibility, but they are not important to the argument we are building.
Similarly, from (2), we probably do not even know the full duration of action yet. Some studies suggest that after about seven months, the vaccines are entirely useless, others suggest they last for longer or shorter periods. It may be better to speak in terms of half-life and say that half their VE is gone after about four months, but even this point would be subject to debate. The drop off of VE may happen more suddenly and be around six months. Again, the time period does not matter all that much. If the vaccines lasted several years, then it might (probably still would not), but no one can truly argue the vaccines are effective for more than a year. Otherwise, the booster push would have occurred much later, and there would not be widespread reports of the vaccine being completely ineffective in many places.
Arguments you may encounter
One argument that the vaccine enthusiasts may make is that vaccines improve outcomes. This argument is weak at best. The earliest incarnation of the argument that I remember came right after the Pfizer trials — trials not designed to examine this possibility at all. In fact, as far as the vaccine being a therapeutic, I have not seen any reliable research suggesting as much. To actually run such a trial, many variables need to be controlled for, and alternative therapeutics need to be considered. There is a lot of data that suggests that the outcomes are similar in the vaccinated and unvaccinated that do get the virus, and some research has suggested that the vaccine confers an inferior form of natural immunity after catching the virus.
In short, the research may or may not show the above to be true. Right now though the claim is entirely non-scientific either way. We do not observe the counterfactual of individual outcomes directly. I would not bother arguing this point as it is a black hole. In any case, adverse events from vaccination would make it one of the worst therapeutics of all time for a virus of this nature. Like using chemotherapy for a single cancer cell or killing a fly with a bazooka.
Furthermore, the argument that the vaccine will at least slow the spread of the virus and free up hospital beds is pretty weak. Again, the crusaders will vaccinate many times more people than would catch the virus, and they would do it in a short period of time. Not only do people in the first few weeks of the vaccine catch the virus, end up in the hospital, and die of the virus at a faster rate, but beds will also be needed for those with adverse events. This argument would be easier to take seriously if there was a massive public health push for people to eat well, lose weight, and stay fit and healthy, which will actually free up hospital beds. It would also be easier to take seriously if the crusaders had spent the last few decades preparing for the rising age of the boomer population instead of cutting support services, tying up the hospital administrative system in regulation, and allowing medical associations to create large barriers to entry for prospective students in the medical field.
Rate of reproduction
Now, we need to consider another factor in herd immunity. Rate of reproduction, or R0, is the amount of people the average person that contracts the virus infects. Pinning down R0 for this virus seems to be an exercise in futility. R0 is highly variable. When actual cases (not necessarily confirmed) are dropping in a region, R0 is below 1. When they are rising, it is above 1. There are many factors that contribute to this, but the main factor appears to be seasonality. In some places, R0 will be very low, in other places it will be very high. The fact that it is very high in some places is problematic for herd immunity.
If it were low or near the average R0 of the original strain, which was roughly estimated to be 2.5-3, then a mass vaccination campaign might have been possible with the right distribution. But an average is an average is an average. If the average is 2.5-3, and it is below 1 in some places, that will pull down the average. We can only make a supposition that it was always high, maybe the tests were just bad, as we do not observe the real R0 at any given time, nor is it constant. Over time, the R0 would have dropped naturally as more people acquired immunity, but the vaccine may have caused it to rise especially if the vaccine is creating variants.
But given what the crusaders knew at the time, it, again, does not matter whether the vaccine has increased R0 or if it was the variants, et cetera. They knew that the R0 was only 2.5-3 on average, and it was not a hard ceiling. This is another point just as important as our axioms. Perhaps, if the vaccinations were not rushed, despite the fact that they are non-sterilizing with a limited duration of action, the R0 of the virus would have dropped to a point through natural immunity that the vaccines could have eliminated the virus with ease, assuming that they do not increase the R0. But they were rushed despite an R0 that could potentially rise above the point where the virus could be eliminated with vaccines.
Here is a chart with how the R0 interacts with VE.
The middle figures are the percentage of the population that needs to be vaccinated in order to contain a virus. As you can see with sterilization, not that many people necessarily need to be vaccinated in order to eliminate a virus. Note all the different scenarios where more than 100% of the population needs to be vaccinated; in other words, the virus would not be eliminated in those scenarios with vaccines.
With perfect sterilization, a high R0 does not matter that much. But with a leaky vaccine, it begins to matter a lot more. The crusaders have claimed that we needed about 70% of the population vaccinated to achieve herd immunity, up from around 60% earlier. You can see they were assuming that the R0 was static at around 2.5-3 and the vaccine was 85-95% effective. Neither were truly the case, but as I said, we do not even need to argue that point.
Simultaneity
The important points are that the less effective a vaccine is, the harder it is to achieve herd immunity, and the duration of action is incredibly important. If the vaccines lasted for, say, several years without degrading immunity, then eliminating the virus may have been feasible. The rub? Under perfect conditions, like the assumption that R0 is low and the vaccine remains at a high rate of effectiveness for the duration of its life, we would need to vaccinate the entire population of the world to a high level simultaneously.
It took a year to get the world 50% vaccinated. Those were the easy gains. We would have needed to get every household in every neighborhood in every city in every region in every state in every country of the world above 74% vaccinated if the R0 was a modest 3 at the very ceiling. That was, of course, not possible. Not every place has the same access to resources, distribution mechanisms, or supply chains. Some countries started their vaccination campaigns early, like Israel, and the vaccines were already at the end of their duration of action when other countries really began to get their vaccination programs off the ground.
If people believe the R0 can get above 3, and it most certainly can, and the vaccine is less than 70% effective, and it probably is, then there is no feasible way the vaccine strategy could ever have worked even if we vaccinated everyone simultaneously. We are talking about vaccinating more people than we have in a year, distributed across every region in the world, in the matter of a few months under the assumption that the vaccine is as effective as the manufacturers claim. Again, not possible, and governments pushing for 100% vaccination rates in their own countries does nothing to solve the issue of vaccination in other countries.
There are other problems, though.
Even with the percentage of the population needed to reach herd immunity, it still takes time for the virus to be eliminated from the population. It is most definitely not immediate. And how much time will depend on many complicated factors. During that time, the vaccines may have already reached the limit of their duration of action, and thus, the virus will spread again, making the entire process useless.
The virus can jump from humans to animals. Which means we would also need to vaccinate all the animals that the virus can jump to in the world simultaneously as well. Again, not possible.
Essentially, the crusaders have agreed to keep their countries in a holding pattern, taking boosters until every other country has achieved the required vaccination rates. And because the virus is zoonotic, it will still only provide us with an incredibly short time without the virus if even if their plan works! Meanwhile, people will be racking up adverse events and still getting the virus anyways.
We would have been better off just letting the virus spread through the population without the vaccines because at least then we would not be paying the cost of adverse events. We will reach full natural immunity long before the crusaders plan is achieved because their plan is impossible to achieve.