According to a study published this summer in the American Journal of Gastroenterology, people who use omeprazole are more likely to get COVID-19. (1, 2) The long-term, twice-daily use of PPIs doubles the odds of testing positive COVID-19, even after taking into account a range of sociodemographic, lifestyle and clinical variables. Omeprazole is in a class of drugs called “Proton Pump Inhibitors”, or PPIs, which reduce stomach acid output by 99%. PPIs include brands such as Nexium, Prilosec and Prevacid.