Short version:
Based on the information we currently have, masks are a somewhat reasonable (if annoying) precaution to try and reduce the R0 of the virus, but lockdowns are the wrong strategy. The right strategy is diet, exercise, and supplementation with Vitamin D. Lockdowns make people sedentary and reduce their sun exposure, which is the opposite of what should be happening. COVID-19 is a reaper of sun-deprived, sedentary people.
Now, for the long version:
Vitamin D regulates inflammation, it reduces oxidative stress, and it also up-regulates ACE2. One might think that increased ACE2 could be damaging in a COVID-19 infection, since that is the entry receptor of the virus, however, the down-regulation of ACE2 in COVID-19 leads to tons of inflammation and potassium loss (hypokalemia) from increased Angiotensin II and aldosterone activity. Also, ACE2 is needed to inactivate des-Arg9-bradykinin and prevent the bradykinin storm.
Is a Bradykinin Storm Brewing in COVID-19?
Excess of the inflammatory molecule bradykinin may explain the fluid build-up in the lungs of patients with coronavirus infections. Clinical trials of inhibitors are putting this hypothesis to the test.
Vitamin D deficiency greatly enhances not only the chance of getting sick with COVID-19, but also the severity of the symptoms.
Dysregulation of NADPH oxidase and the production of excessive reactive oxygen species in the blood vessels in implicated in diabetes, hypertension and various other diseases. It prematurely ages the blood vessels.
In order to understand what's happening with COVID-19, it is important to understand how the renin-angiotensin-aldosterone system works, and how NO/ONOO- cycle diseases work.
This stuff is really, really significant, because it gives us a clue to the real cause of COVID-19's disparate severity in some nations compared to others, and it may be almost entirely down to the diet and overall health of a population. Japan has a huge population density, but only 75,000 cases and 1,448 deaths due to COVID-19. The average Japanese diet is full of seafood (Vitamin D) and vegetables (dietary nitrate), both of which reduce inflammation and oxidative stress.
On the other hand, when SARS-CoV-2 gets into the body of an American who's been raised on red meat and processed grains all their life and has prematurely aged blood vessels, chronic inflammation, and hidden malnutrition, Corona-chan just straight-up kills them.
Check this out. COVID-19 severity by race.
COVID-19 causes substantially higher rates of illness and hospitalization in Hispanics and especially African-Americans.
Now, what are the rates of Vitamin D deficiency in the US by race?
41.6% of Americans are Vitamin D deficient, but 62.9% of Hispanics and 82.1% of African-Americans.
African-Americans also have much higher rates of obesity, chronic inflammation, oxidative stress, hypertension, and diabetes than other races.
We are closing in on effective treatments that greatly reduce the morbidity and mortality of COVID-19. Accordingly, the case fatality rate is dropping as doctors adopt new practices that enhance patient survival.
The ideal prophylaxis for COVID-19 is diet (especially incorporating more fish, spinach, beets, kale, et cetera, into one's diet), exercise, and adequate sunlight. All this virus has done is reveal how incredibly unhealthy we already are. If someone ends up in the ICU with COVID-19, basically the only treatment that works is pumping corticosteroids like dexamethasone into them until their immune system calms down and stops destroying their tissues.
