Opinion | These Coronavirus Exposures Might Be the Most Dangerous
The importance of viral dose is being overlooked in discussions of the coronavirus. As with any other poison, viruses are usually more dangerous in larger amounts. Small initial exposures tend to lead to mild or asymptomatic infections, while larger doses can be lethal.
From a policy perspective, we need to consider that not all exposures to the coronavirus may be the same. Stepping into an office building that once had someone with the coronavirus in it is not as dangerous as sitting next to that infected person for an hourlong train commute.
Both small and large amounts of virus can replicate within our cells and cause severe disease in vulnerable individuals such as the immunocompromised. In healthy people, however, immune systems respond as soon as they sense a virus growing inside. Recovery depends on which wins the race: viral spread or immune activation.
Humans also exhibit sensitivity to viral dose. Volunteers have allowed themselves to be exposed to low or high doses of relatively benign viruses causing colds or diarrhea. Those receiving the low doses have rarely developed visible signs of infection, while high doses have typically led to infections and more severe symptoms.
Low-dose infections can even engender immunity, protecting against high-dose exposures in the future. Before the invention of vaccines, doctors often intentionally infected healthy individuals with fluid from smallpox pustules. The resulting low-dose infections were unpleasant but generally survivable, and they prevented worse incidents of disease when those individuals were later exposed to smallpox in uncontrolled amounts.
Despite the evidence for the importance of viral dose, many of the epidemiological models being used to inform policy during this pandemic ignore it. This is a mistake.
****
This worth a read. Intentional exposure to very low doses of viruses lead to mild or asymptomatic infections. Intentional exposure works like a vaccine, although at a higher risk.
We live in a dangerous time. The coronavirus is projected to infect 60% of the American population, unless checked. Checking the virus has historic economic cost as we have seen, and the American government is unlikely to replay these unprecendented actions, IMO. The virus will be back in the fall. Maybe there will be an effective treatment by then, maybe not.
Once we get past this monthlong outbreak, should younger, healthy, working Americans be intentionally be exposed in this way, followed by a 14 day quarantine. Get them back to work, get the economy going, and increase the herd immunity. Would a young bus driver prefer a controlled dose, quarantine, and future immunity; or a random and potentially high virus dose of what they encounter from passengers?
In Massachusetts, 95% of deaths are those over 60. Deaths under 60 are typically accompanied by pre-existing conditions (note I realize MA numbers don't reflect numbers in poorer communities for many reasons; I'm noting the only age/death numbers I can find in the U.S). Despite media efforts of playing every story of a young person's CV death in a country of 330 million, this virus primarily attacks weakened immune systems, which increase in numbers greatly with age.
I hope more study is done on this over the next few months, to define risk and reward for this approach.