Findings from a study in Sweden provide one possible explanation for why some health care workers who were in contact with COVID-19 patients every day remain uninfected, even though they were not vaccinated against the disease. “The reason why some of the staff did not contract the disease seems to have been that IgA (immunoglobulin A) was present in their respiratory tract,” announced the University of Gothenburg in a release. “These antibodies, found naturally in the secretions of mucous membranes in the airways and gastrointestinal tract, can protect the body by binding to viruses and other invading organisms.” Researchers at the university’s Sahlgrenska Academy examined 156 unvaccinated employees at five primary care health centers belonging to the Nötkärnan group in the Gothenburg area. The results were published in the European Journal of Immunology. “We all have IgA. It’s found on the mucous membranes, and COVID-19 is an infection that spreads via those membranes,” Christine Wennerås, an …