Health care workers treating coronavirus patients are obviously at high risk of contracting the disease. This paper studies the prevalence of the disease in Spanish health care staff. (Medrxiv Paper) The researchers conducted both an infection test and an antibody study. Out of 578 workers, 39 had a previous diagnosis of coronavirus disease. 14 had a positive infection test as part of the study and 54 had antibodies, and 21 of these had not had a prior positive infection diagnosis. Antibodies were correlated with age and were stronger in symptomatic than asymptomatic individuals, although study numbers were small. In total, about 11% of the workers had been infected. The authors had expected a greater incidence of the disease, but it may be that if the health care workers took adequate precautions, they were less likely to be exposed, or, once again, it may be that many people just aren’t very susceptible to infection, even after exposure.
The second study relates to the presence of T cells, another part of the immune system, that react to coronavirus. (Medrxiv Paper) The researchers found the T cells not only in infected individuals but in some who had not been infected, suggesting some cross-reactivity in regard to other coronavirus strains. The authors note that the finding of cross-reactive T cells may explain the high rates of asymptomatic infection in some people, especially younger ones.