Two human challenge trials were done during the 1918 Spanish flu season by two independent groups of doctors in Boston (62 volunteers) and San Francisco (50 volunteers). Researchers tried every way to infect healthy people by dripping mucous and bodily fluids from Spanish flu patients into the volunteer's eyes, noses, and throats. Regardless of how they tried to infect people, none of the participants became infected.
​
During the COVID-19  pandemic, a SARS-CoV-2 human challenge study was conducted and published in Nature in 2022. Thirty-six healthy volunteers were infected with the virus through their nose—half remained uninfected and the other half had only mild symptoms. These trials demonstrated that just because you are exposed to a bacteria or virus, it doesn't mean you have to get sick. As Louis Pasteur allegedly stated on his death bed, "Bernard Bechamp was right: The pathogen is nothing; the terrain is everything." This means that the most important factor in contracting disease is the overall health of the body, not exposure to a particular bacteria or virus. 

Interestingly, the word 'breakfast' means to 'break' the overnight 'fast' of not eating while sleeping. Many cultures and religions include regular programs of fasting. Muslims fast from dawn to dusk during the month of Ramadan. Chinese Buddhists fast after their noon meal until the following morning. Members of The Church of Jesus Christ of Latter-day Saints fast a minimum of one Sunday every month of the year. Hippocrates advocated against eating while sick, stating that "to eat when you are sick, is to feed your illness." The adage to "starve a cold" but feed a fever" has been around for aeons. Doctors with the Front Line COVID-19 Critical Care (FLCCC) Alliance treating long COVID and COVID vaccine injuries advocate fasting as the most important therapy in their first-line treatment approach. The latest studies reveal that fasting offers many advantages beyond weight loss. Fasting reduces inflammation, boosts immunity, enhances cognitive function, and lowers the risk of cancer.

Bone marrow is like a busy manufacturing plant producing and sending blood cells out the door as fast as it can. The stem cells in the bone marrow can produce various types of cells, including red blood cells (RBCs). These RBCs carry oxygen throughout the body. The stem cells also produce all of the various immune system cells, including white blood cells that support and defend the body against invaders. When bone marrow stem cells produce abnormal white blood cells, the disease is called leukemia. Leukemia is the 10th most common cancer in the United States. It comes in a variety of forms, but all of them consist of an excessive amount of abnormal white blood cells in the body's blood-forming tissues—the bone marrow and lymphatic system.

In 1817, Dr. James Parkinson described six individuals living in London who had the disease which was later named after him. In 2015, over 6 million individuals live with it. The disease is expected to grow to 12 million by 2040. According to the Global Burden of Disease study, neurological disorders are the leading source of disability worldwide. The fastest-growing one is Parkinson's disease (PD). The percentage of Americans 65 and older with the disease nearly quadrupled from 4.1 percent in 1900 to 16 percent in 2019. Many consider it a real pandemic.