Study: "Supershedders" Minority Spreads Most COVID

Facts

• A new study published in Lancet Microbe has provided a wide range of information on the viral transmission of COVID, notably showing that a relatively small group of “supershedders” spews far more pathogens into the air, spreading the disease, than others.¹
• The controversial “challenge study” — which involved intentionally infecting subjects with the virus — observed 36 healthy, young patients (ten female and 26 male), 18 of which became infected. Notably, two participants emitted 86% of the total airborne virus.²
• Those two individuals only experienced mild symptoms, and the study adds credence to the idea that individuals can contribute to “superspreading events” in a way that is disproportionate to the number of people they come in contact with.³
• The study also showed the value of rapid tests as none of the participants emitted detectable levels of the virus in the air before testing positive, and only a small number left a detectable amount on their hands, on surfaces, or on masks.¹
• The “challenge study” format has been used in multiple COVID studies, with some objecting to them on ethical grounds. Such studies have been restricted to low-risk subjects and provide a controlled environment to gather information on disease development.⁴

Sources: ¹Nature, ²The Lancet Microbe, ³IO, and ⁴The Conversation.

Narratives

• Narrative A, as provided by JAMA Network. Challenge trials create a moral dilemma and are directly contrary to the all-important Hippocratic Oath to do no harm. With a disease as novel as COVID, there is not enough information to provide patients with the appropriate knowledge to provide informed consent. These types of studies have a dark history as humans were used as lab rats in the past, and they can even be used today to exploit vulnerable populations. Challenge studies do not provide enough value to offset the moral questions.
• Narrative B, as provided by Clinical Trials Arena. While there are obvious reasons to question the ethics of challenge trials, scientists have developed a model that can conduct them in a way that gives vital information on vaccine research and development while keeping subjects safe. Challenge trials on COVID have already paved the way for some of the world’s most innovative research all while keeping the participants safe. Doctors and scientists must do everything they can to pursue knowledge in the safest way possible.