Professor John Nicholls discusses asymptomatic virus carriers, stating that about one third of PCR positive SARS-CoV-2 patients in China do not develop symptoms. These carriers are important to study as they may silently spread the virus in the community. Understanding the true extent of infection is crucial for determining the severity of the virus and the percentage of patients who may require intensive care. As some regions move past the initial stage of acute infections, more attention is being given to finding out what percentage of the general population has antibodies to the virus.