What does scientific evidence mean in the Covid-19 pandemic?

In a rush to comment on SARS-CoV-2 and Covid-19, many experts have erred. Throughout the course of this pandemic there have been several prescriptive pieces based on scientific research, typically on the lines of ‘what must the government do’. This piece Majority Indians have natural immunity. Vaccinating the entire population can cause great harm is a fine example of it. If this kind of speculative information makes it to the epidemic response and policy advisory processes of any country, even the last few corners of hope in fighting the pandemic will be lost. 

The authors asserted that ‘The scientific evidence is overwhelming that natural immunity attained after recovery from Covid infection is effective and long lasting.’ What does an ‘overwhelming evidence’ mean? How does one confirm that an evidence is overwhelming then the universal set is not yet known? 

Prediction in itself is not a problematic idea, but when they are delivered with a certainty and force that has the likelihood of  action attached, it is frightening. The modern day crop of experts can learn a fair deal about the nature of scientific knowledge and the process through which that knowledge is generated from those who did truly push the boundaries and opened new portals of scientific knowledge in the previous centuries. This needs to be emphasised because the deficit in scientific training in our institutions of higher learning is known all too well. So, may be many of us missed out on learning the seemingly minor stuff about nature of science, scientific enquiry and the temper it requires to think of a problem beyond the narrow gains of claim. Our science needs more doubt than certainty. It is just naive to be prescriptive based on results from a transient phenomenon. 

Here is an instance of it.

In 1944, three scientists – Avery, MacLeod and McCarty, of the Rockefeller Institute in New York published a paper claiming that the ‘transforming factor’ of pneumococcus consisted of pure DNA. These were early days of research on the structure of DNA and figuring out the whole process through which a genetic material as DNA transcribed itself into proteins. In the paper, the authors were cautious in interpreting their results. 

In his autobiography What Mad Pursuit published in 1989, Francis Crick writes that the conclusion was not immediately accepted. It was argued that the evidence from the study was ‘flimsy’. He elaborates – 

The fact that these transformations were often unreliable, tricky to perform, and only altered minority of cells did not help matters. Another objection was that the process had been shown to occur just in these particular bacteria. Moreover, at that time no bacteria of any sort had been shown to have genes, though it was discovered not long afterward by Joshua Lederberg and Ed Tatum.

Explaining this background, Crick makes one of the most important remarks that has bearing, perhaps of greater magnitude, in this pandemic. He writes – 

In short, it was feared that transformations might be a freak case and misleading as far as higher organisms were concerned. This was not a wholly unreasonable point of view. A single isolated bit of evidence, however striking, is always open to doubt. It is the accumulation of several different lines of evidence that is compelling.

Crick’s recollection is instructive. On the state of protein structure and function research, he observed – 

…many of the properties of proteins and genes just outlined were not known for certain.’ All of this seemed plausible and most of them seemed very probable, but, as in most problems near frontiers of research, there were always nagging doubts that one or more of these assumptions might be dangerously misleading.

‘In research the front line is almost always in a fog.’ Crick observed.

Cutting ahead to 28 Feb 2020, in an editorial titled ‘Covid-19 – Navigating the Uncharted‘ for the New England Journal of Medicine on 28 Feb 2020, Fauci, Lane and Redfield observed – 

The Covid-19 outbreak is a stark reminder of the ongoing challenge of emerging and reemerging infectious pathogens and the need for constant surveillance, prompt diagnosis, and robust research to understand the basic biology of new organisms and our susceptibilities to them, as well as to develop effective countermeasures.

It is noteworthy that the authors called for scientific evaluation and ethically sound studies in the research effort that had begun by the end of February 2020 when it was nearly certain that the SARS-CoV-1 virus was heralding a whole new pandemic on the planet. 

Critical to moving the field forward, even in the context of an outbreak, is ensuring that investigational products are evaluated in scientifically and ethically sound studies.

By April 2021, a lot has been discovered about the SARS-CoV-2 virus. The pace with which science has progressed in this pandemic is phenomenal and unprecedented. CEPI’s COVID-19 Vaccine Development Landscape describes the state of R&D efforts that went live as early as March 2020.

The genetic sequence of the virus was published on 11 January 2020. The first Covid-19 vaccine candidate entered human clinical testing on 16 March 2020. The fastest vaccine development before this was for Ebola. It took five years to develop that vaccine. The average vaccine development time scale is ten years long. 

These are certainly some of the best times in terms of scientific capability and readiness of the humankind to respond to pandemics as Covid-19. However, it has also necessitated much more responsibility in scientific research and communication, because the scales (of time, space and need) that are seen in these times can mean very rapid gains as well as very rapid losses. 

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