Covid 19: Why can’t they do simple mathematics?

For a student of science like me, whatever is happening with the pandemic and whatever is being said reveals how human mind works, how we perceive science, how we ask questions and what satisfies our questions.

A number of statements are being made by the mainstream Covid epidemiologists which are actually not supported by data. The same data can be interpreted differently. The different possible interpretations need to be treated as competing hypotheses and tested by making additional differential testable predictions. This is the core method of science. But the human mind has not evolved to follow the scientific method and pursue truth. It has evolved to make stories. The stories need to satisfy some audience. The attempt of an investigator is to satisfy his/her present audience with minimum effort. Different audiences have different satisfaction thresholds. If your story satisfies your audience, you stop there. You stop looking for alternative interpretations. You don’t need to test them. You don’t need to recheck whether your story is consistent enough with evidence. Whether there are any anomalies and whether they are serious enough to raise doubt on your story is no more a concern as long as nobody challenges your story. If someone challenges the story the first line of defence is to say the person is not credible, ignore him or better brand him as ‘anti-science’. Such branding works most of the time, so that you don’t really have to take trouble to pursue scientific method further. Scientific solutions are costlier. Social solutions are cheaper.

Take the example of the new wave which is said to be caused by the variant omicron. Is this a well tested hypothesis? By the methods of science that we teach undergraduates, any hypothesis can be tested against a null hypothesis. Different variants keep on arising and vanishing in a population owing to chance as well as by selection, and selection can happen due to not one but multiple reasons. In viruses, there is selection within a cell, during cell to cell transmission, there is selection on dose of the virus being transmitted, time for which the host remains infective, time for which viral particles survive outside the host, how the virus elicits immune response, whether and how virus evades host immunity and so on. The selection is necessarily multi-level with additive as well as multiplicative components and is really a challenge to selection dynamics. Further there can be trade-offs between any of these. Natural selection on viruses is much more complex than the prevalent naive thinking that a more infectious virus will win the race.

As the wave goes up and down, new variants keep on arising. Many variants increase their abundance while the wave is downwards. So new variants keep on arising during any part of the wave and by chance some variant may happen to ride a rising wave. This should be the null hypothesis, only by rejecting which we can say that a given variant is certainly responsible for a wave. I could not find any such analysis in literature but a story seems to be accepted that the new wave is because of omicron. The increase in proportion of omicron is not always accompanied with increased transmission. For example, in Russia, between 29th November 2021 and 11th Jan 2022, the Omicron proportion increased from negligible to 50 % while mean number of cases per day came down by more than half. Omicron accompanied a downward and not upward trend in total number of cases.

Even in countries where omicron accompanied a rise in the wave, omicron does not account for the rise. In India, for example between Dec 29th and Jan 20th the incidence rose about 40 fold and omicron proportion increased from negligible to 77%. By simple arithmetic, a rise to 77% can explain only about   4 fold increase in total incidence. During this time the delta variant incidence also increased by over 9 fold. If the new wave was caused by omicron, why did we see the delta cases going up 9 fold? This is simple arithmetic that we teach in secondary schools. Perhaps for experts in this field using simple mathematics is too below their dignity. They have to use sophisticated models to impress everyone. Simple arithmetic poses a major anomaly for the hypothesis that the new wave is “caused” by omicron. Data only show that omicron is associated with the new wave, that too in some countries, not everywhere. It is equally likely that the selective environment during the new wave allowed the spread of omicron. So the wave is the cause and omicron the consequence. Alternatively the association is only coincidental and there is no causal association between the two. Unless such alternatives are considered as competing hypotheses and ruled out, ‘omicron caused the new wave’ is not a scientific statement, by the core principles of science. It’s only a story that has convinced most people, therefore it is considered scientific as of today.

This is how science works most of the time. It is a complex social process that sometimes, particularly when convenient, uses the fundamental principles and methods of science. The methods of science is the tool used by people whose prejudices, interests and agendas decide the emerging inferences.

Then what caused the new wave? There are several alternative possible reasons. We showed with a model earlier that the wave pattern is possible by considering immunity as a continuous rather than a binary variable. In reality, immunity IS graded and not binary. By this model, waves arise and wane even without a new variant. So it is very much possible that waves arose as a part of the population dynamics of what we called in the model as ‘small immunity effects’. Alternatively it is also possible that the vaccines give only systemic immunity, but respiratory mucosal immunity has a different set of mechanisms which the vaccine administered by injection does not strengthen much. As a result when the low tide lingers around for sufficiently long period people tend to lose mucosal immunity, but systemic immunity is still there. Therefore a new wave begins with whatever variant is around, but does not lead to serious symptoms among the vaccinated. If this hypothesis is true, we should see increase in cases of all prevalent variants, though not to the same degree because different variants have different competitive abilities. Also even where the incidence is declining, the more competitive variant will become commoner. I am not saying this IS the reason. I am saying that being open to different possibilities and testing them with differential predictions is how science should work, but during Covid times scientists themselves seem to have forgotten the methods of science. I am happy that the Covid epidemiologists are providing a science teacher like me several examples to demonstrate how science should be and should not be done. It is also enriching in me the curious student of social psychology of science. It is interesting to see how the community of scientists actually works besides the principles of science.

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