Positive: A virtuous cycle follows from social distancing and isolation measures leading to low-inoculation infections that still promote immunity. A new kind of herd immunity might emerge with a lower fraction of disease. The fraction of infections that lead to serious disease, including mortality, may not be a fixed number as most modeling now assumes. The underlying biological mechanism might be akin to Variolation. Infections that result consequent to social distancing not only arise more slowly but also offer more protection at a cost of fewer symptoms. A plausible implication is less harm in low population density areas. Conversely, high-inoculation infections could be the reason that health care workers are at special risk. An implication is the need for “Precision Public Health” in understanding the microbial environment of assisted care homes, cruise ships, aircraft carriers, and expeditions. Plausibility 2; Potential Importance 1, Testability 2-3

Negative: Suppose antibody response in some cases makes things worse because some antibodies that bind to the virus facilitate uptake and productive infection. Such mechanisms are known for other viruses, including related coronaviruses in vitro but not documented specifically for the novel coronavirus. Plausibility 2, Potential Importance 1 Testability 2