COVID-19: Immune Response Among the Asymptomatic / Latino Patients / Tocilizumab

By Kelly Young

Edited by Susan Sadoughi, MD, and André Sofair, MD, MPH

Have a look at some of the recent developments in COVID-19:

Immune response in asymptomatic people: Infected people who are asymptomatic develop a weaker immune response than people who have symptoms, and the response may not be long-lasting, suggests a study in Nature Medicine. Researchers studied 37 asymptomatic participants who tested positive in China. Asymptomatic cases shed the virus (positive nasopharyngeal swab) for a median of 19 days, which was significantly longer than symptomatic cases. Within 2–3 months of infection, most patients saw a reduction in immunoglobulin G (IgG) and neutralizing antibody levels. At 8 weeks, more asymptomatic than symptomatic patients were seronegative for IgG (40% vs. 13%).

Prevalence among Latinos: In the Baltimore/Washington, D.C. area, the Latino community has been disproportionately affected by COVID-19, according to a JAMA study. Among 38,000 high-risk or symptomatic people who were tested for SARS-CoV-2 in one health system from March to May, 16% were positive. The positivity rate was significantly higher for Latino patients (43%) than for white patients (9%) or Black patients (18%).

Tocilizumab: The monoclonal antibody tocilizumab showed mixed results in treating COVID-19 in a small, retrospective study in EClinicalMedicine. Researchers examined roughly 50 patients admitted to one hospital for COVID-19 in March and April. Patients given tocilizumab were compared with patients not given the treatment. Most patients received hydroxychloroquine and azithromycin. During a median 10 days' follow-up, there was no significant difference between the treatment groups in improvement in oxygen support, discharge, or mortality. Tocilizumab was associated with shorter median duration of vasopressor support (2 vs. 5 days).