Correlation is not Causation! Are we the victim of Post Hoc Fallacy amidst pandemic, COVID-19?
A week back I wrote a small article about Post Hoc Fallacy where I had explained a human tendency to find patterns which leads to wrong conclusions e.g. relation between rain man dance vs rain and increase in global warming vs decline in the number of pirates. One can read the same in the article below.
Today we are fighting with a deadly pandemic and it becomes all the more necessary to debunk one of the similar hypothesis which surfaced the internet and social media recently making us believe to be true in battling COVID-19.
Correlation between BCG vaccinations & the rates of COVID-19 morbidity and mortality
The study done by the New York Institute of Technology (NYIT) to understand the severity of the impact might have fallen for the Post Hoc Fallacy.
“We found that countries without universal policies of BCG vaccination, such as Italy, the Netherlands, and the United States, have been more severely affected compared to countries with universal and long-standing BCG policies,” noted the researchers led by Gonzalo Otazu, assistant professor of biomedical sciences at NYIT.
The study concluded that a combination of reduced morbidity and mortality could make the BCG vaccination a revolutionary in the fight against corona virus.
Several institutes across the world started to find a theoretical base to this correlation. The scientific community especially the medical scientists understand that a mere correlation cannot be a causation. The theoretical base to conclude such a hypothesis needs to be more subjective than just a mere correlation. However, the pattern was already out in the media and we found a pattern. As expected, theories started building up even before any conclusive subjective research could be proven.
The Maharashtra government in India approached the Indian Council of Medical Research (ICMR) and the Drug Controller General (DCG) with an application seeking permission to use BCG vaccine for clinical trial on Covid-19 patients. The decision was taken following “positive results” of research carried out by experts at the Haffkine Institute in Mumbai.
Amidst the confusion between scientists trying to find a potential conclusive base for such studies, some media houses and social media has already proved the effectiveness of BCG against COVID-19. However, on 12th April 2020, WHO clarified the doubts:
There is no evidence that the Bacille Calmette-Guérin vaccine (BCG) protects people against infection with COVID-19 virus. Two clinical trials addressing this question are underway, and WHO will evaluate the evidence when it is available. In the absence of evidence, WHO does not recommend BCG vaccination for the prevention of COVID-19. WHO continues to recommend neonatal BCG vaccination in countries or settings with a high incidence of tuberculosis.
Let’s hope a better sense prevails and our strengths don’t fall short against the Post Hoc Fallacy!
