SARS-CoV-2 and the Neanderthals

July 15, 2022

I found a fascinating scientific article^[1] that provides a possible explanation for some of the observed population differences in the susceptibility to SARS-CoV-2 infection and the severity of COVID-19 illness.

The original assumption of the authors of the article is that the strongest genetic determinants of COVID-19 known up to the beginning of their research have had similar effects on individuals across the globe; but people with non-European ancestries have experienced a higher risk of developing severe forms of COVID-19.

It is well-known that anatomically modern humans interbred with archaic hominins, such as Neanderthals and Denisovans, on multiple occasions and in several locations^[2]. As a result, all non-African groups share ∼2% Neanderthal ancestry in their genomes, whereas some south-east Asian and Oceanian populations have accumulated up to 5–6% of combined (Neanderthal and Denisovan) archaic ancestry^[3].

The article concludes that “past demographic and selection events characterizing the history of human species, including admixture with archaic humans, such as Neanderthals, facilitated modern human adaptation to the threats imposed by ancient pathogens”. Furthermore, “the genetic legacy of ancient admixture with Neanderthals around 50,000 years ago still affects the health of humans nowadays, including the specific context of the COVID-19 pandemic”.

References:

1. Kerner, Gaspard, and Lluis Quintana-Murci. “The genetic and evolutionary determinants of COVID-19 susceptibility.” European Journal of Human Genetics 30.8 (2022): 915-921.
   https://www.nature.com/articles/s41431-022-01141-7
2. Dannemann, Michael, and Fernando Racimo. “Something old, something borrowed: admixture and adaptation in human evolution.” Current opinion in genetics & development 53 (2018): 1-8.
3. Choin, Jeremy, et al. “Genomic insights into population history and biological adaptation in Oceania.” Nature 592.7855 (2021): 583-589.