https://neurosciencenews.com/rna-coronavirus-age-16373/
Tiny RNA that should attack coronavirus diminish with age and disease
here is the article discussed
https://www.researchgate.net/publication/340917045_Endogenous_deficiency_of_glutathione_as_the_most_likely_cause_of_serious_manifestations_and_death_in_patients_with_the_novel_coronavirus_infection_COVID-19_a_hypothesis_based_on_literature_data_and_ow