Parasitic diseases are highly prevalent in Brazil [1]. Also, as quoted in [2], "Helminth [ie worm] infections are among the most common infectious diseases. Br

Parasitic diseases are highly prevalent in Brazil [1]. Also, as quoted in [2], "Helminth [ie worm] infections are among the most common infectious diseases. Bradbury et al. highlight the possible negative interactions between helminth infection and COVID-19 severity in helminth-endemic regions and note that alterations in the gut microbiome associated with helminth infection appear to have systemic immunomodulatory effects. It has also been proposed that helminth co-infection may increase the morbidity and mortality of COVID-19, because the immune system cannot efficiently respond to the virus; in addition, vaccines will be less effective for these patients, but treatment and prevention of helminth infections might reduce the negative effect of COVID-19. During millennia of parasite-host coevolution helminths evolved mechanisms suppressing the host immune responses, which may mitigate vaccine efficacy and increase severity of other infectious diseases." It seems strange that the referenced study did not consider the possible confounding factor of parasitic infection. [1] https://pubmed.ncbi.nlm.nih.gov/34105625/ https://pubmed.ncbi.nlm.nih.gov/34105625/ [2] https://astralcodexten.substack.com/p/ivermectin-much-more-than-you-wanted https://astralcodexten.substack.com/p/ivermectin-much-more-t...