Published in Science Immunology last week, the study by German researchers found that mRNA boosting induced a high level of so-called IgG4 antibodies, a subclass known for prompting a mild immune response, in two cohorts of several dozen healthcare workers.
The "shift" to this IgG subclass was "not seen with adenovirus vector vaccines" in the study, Scripps Research Translational Institute Director Eric Topol, who was not involved in the research, tweeted while cautioning that "clinical significance is not known."
