India is a land of unity in diversity. India, being the world’s second most populous country is uniquely distinct for its varied diversity. Be it geographic or climatic diversity, be it the diversity in languages, religions and cultures of its people, or be it the genetic diversity as evident recently, after all it is our very diversity that imparts strength to our oneness [1].

In the recent times, India has emerged as an outlier in the spread of COVID-19. Owing to the multifactorial influence, there is occurrence of low severity of COVID-19 infection among Indians.

Firstly, broad-based immunity in the Indian population due to the extensive microbial load. The Indian population has been exposed to a vast variety of pathogens, including bacteria, parasites and viruses leading to the generation of broad specific memory T-cells in the system, ready to attack additional foreign invaders. For example, the three main killers of Tuberculosis, HIV and Malaria have plagued India, Africa and several countries in the Southern hemisphere much more than the European and North American nations. In the context of CoV-2 coronavirus, the beneficial role of chloroquine and hydroxychloroquine has been much talked about and debated, while there has already been an extensive usage of this drug at the community level in India -- this too may have been proved beneficial ultimately.

Secondly, epigenetic factors that include environment and food habits may also play a beneficial role for countries such as India; much literature is already available in Ayurveda and other Indian systems of medicine on the definitive beneficial effects of Indian spices in augmenting immunity. Environmental factors include  a  paradox  of  better  sanitation leading to poorer immune training, so poor hygiene leads to low covid death rate in India paradoxically. Food habits include more usage of natural unproceesed raw spices like Turmeric, black pepper etc.  which have aromatic antioxidants like curcumin and piperine as active compounds. These have incredible health benefits like boosting cognitive function, fighting body-wide inflammation, supporting cardiovascular function, promoting youthful radiant skin, supporting joint and muscle health, boosting detoxification, promoting healthy mood balance and supporting natural weight loss.

Thirdly, and most important, is the Extensive diversity of HLA in the Indian population with existence of several ‘novel genes’ [2] and ‘unique haplotypes [3]. In other words, there is a pivotal role of immune response genes in imparting the genetic diversity in the Indian population. These genes are collectively referred to as comprising the human leucocyte antigen system or simply, the HLA genes. Their main biological function is to present invading foreign antigens to the immune systems, since T-cells, which act as the body’s soldiers come into play only when pathogens are presented to them in a more formal manner in association with HLA genes. In other words, the pathogen must first attach to compounds created by HLA genes before T-Cells attack it. If no such compounds are produced by the body, then the T-Cells are 

ineffective. As a consequence of the microbial load, the Indian population possesses a high genetic diversity of HLA, much more extensive than Caucasian populations. Indeed, there is a marked presence of several novel HLA genes and their alleles in the Indian population, most of which do not occur in other ethnic groups. Such genetic diversity of HLA could affect viral fitness.

All in all, I would conclude that although India being a developing nation, has emerged as outlier in the spread of COVID-19 owing to unity in diversity at various levels including genetics.

1. Malhotra, K.C. “Morphological Composition of the People of India.” Journal of Human Evolution, vol. 7, 1978, pp. 45–63.

2. Adamek, M. et al. “Seven Novel HLA Alleles Reflect Different Mechanisms Involved in the Evolution of HLA Diversity: Description of the New Alleles and Review of the Literature.” Human Immunology, vol. 76, no. 1, January 2015, pp. 30–35, https://doi.org/10.1016/j.humimm.2014.12.007.

3. Rani, R. et al. “Molecular Diversity of HLA-A, -B and -C Alleles in a North Indian Population as Determined by PCR-SSOP.” International Journal of Immunogenetics, vol. 34, no. 3, June 2007, pp. 201–208, https://doi.org/10.1111/j.1744-313X.2007.00677.x.