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For over 3 years, the Covid-19 pandemic felt like a world war and has taken close to 7 million lives, disabled many more people, and caused innumerable economic losses around the globe. What can we learn from this tragedy? Are we ready for another Covid-19-like pandemic? Studies show that the majority of people with SARS-Cov-2 infection either show no symptoms or only mild to moderate clinical manifestations; only a small percentage develop severe Covid-19 disease, indicating that the clinical severity of Covid-19 disease is not determined only by the SARS-Cov-2 virus, but more importantly by how the host responds to the viral infection, what is known as natural immunity. Research of what enhances or weakens the natural immunity against viral infections and the practical application thereof is an important lesson one can learn from the pandemic. Research of natural immunity enhancing factors is summarized in this paper. One key characteristic of natural immunity against viral diseases is its non-specificity. The importance of this non-specificity helping to prevent and treat other infections of known or unknown viruses is also discussed. Calls for the clinical application of safe and inexpensive nutrients such as vitamin C in the prevention and treatment of Covid-19 have met significant resistance and objection from the medical authorities and the media since the pandemic outbreak. The main objection is the perceived lack of research and the absence of regulatory approvals. This raises a fundamental philosophical question: what is the primary goal of the medical profession? Facing a new viral pandemic like Covid-19 with no prior research, let alone any approved treatments, why is there opposition to known safe, inexpensive, widely available and often effective nutrients like vitamin C? Why are case reports and case series discounted or ignored rather than explored further to try to help more people? Is such objection protecting consumers or harming the public? Statistics show that viral epidemics and pandemics are occurring more frequently, with a recent review of epidemics and pandemics since 1600 concluding “ the yearly probability of occurrence of extreme epidemics can increase up to threefold in the coming decades.”1. When the next Covid-19-like pandemic of a new virus hits us, are we going to repeat the Covid-19 tragedy? Can improved emphasis on nutritional interventions to prepare for and respond to disease outbreaks mitigate future pandemics?
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