SARS-CoV-2, commonly known as Covid-19, is a novel coronavirus first identified in Wuhan, China in late 2019. It is a member of the family of coronaviruses that includes Middle East Respiratory Syndrome (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS-CoV). The virus is thought to have originated in bats, and is spread mainly through close contact with an infected person through respiratory droplets, such as sneezing and coughing. There is open scientific discussion as to whether the virus may have escaped from a research lab. ^{1) 2) 3)}

The symptoms of Covid-19 vary from mild to severe, and can include fever, cough, and shortness of breath. In more severe cases, the infection can lead to pneumonia, severe acute respiratory syndrome, kidney failure, and even death. Several treatments and prevention measures that can help patients to recover faster in case of infection are currently available. It is important that a correct home therapy is begun as soon as possible, under the supervision of competent doctors, this makes a lot of difference to avoid complications. ^{4) 5)}

The World Health Organization declared Covid-19 a pandemic on March 11, 2020. Since then, the virus has spread rapidly, resulting in over 20 million confirmed cases. In countries where this new disease was not cured correctly and in a timely manner many thousands of people died.

Scientific studies have confirmed that in countries or regions where vitamin D levels in the population are good the severity of symptoms is very low. So this is suggested to public authority as the first way of prevention to be adopted. ^{6) 7) 8) 9)}

This virus, as other coronaviruses, has a high rate of mutations, so during time many variants of the virus have been classified and for this reason the epidemy had several waves.

Co-infection led in early 2023 to 251 recombinant lineages, with XBB prevailing. XBB.1 and XBB.1.5 caused a surge in COVID-19 cases in Maharashtra, India. A highly transmissible XBB.1.16 sub-lineage with specific spike mutations was identified, explaining the outbreak. ¹⁰⁾

These variants completely escape antibodies obtained from artificial immunization, but usually the illness is very mild, when the immune system is efficient. As with flu or Omicron it can be useful, to have faster recovery, the intake of natural supplements like vit C, vit D and N-acetylcysteine. ^{11) 12) 13) 14)}

The advice of the family doctor is to be asked, choosing a good doctor. In 2023 more and more doctors are conscius that vaccination can bring problems like negative protection, headache, myocarditis, thrombosis, chronic fatigue or Bell's palsy to name some of the most often detected issues. ^{15) 16) 17) 18)} So the doctors who are up to date will in most cases suggest other ways of prevention, first of all checking that the patient has sufficient levels of vitamin D. This is one of the most important things that makes the real difference. In fact patients with acceptable levels of vitamin (≥40 ng/mL) were 14 times less likely to have severe or critical disease than patients with insufficient levels (<20 ng/mL). ¹⁹⁾ Ask your doctor to read these studies in the case he is not yet aware of them.

Currently the older strains do not circulate anymore because they have been replaced by Omicron variants and derived descendents, for example Arcturus, which are milder and have higher contagiousness, also among people that received artificial immunization, because of the high pace of mutation of the virus. These new variants have a big evolutionary advantage compared to the original version of the virus.

A Danish cohort study demonstrates that breakthrough infections can not be avoided. Artificial overstimulation of the immune system with older strains can even lead to negative protection, aftern some months, when new variants emerge. ²⁰⁾

A new study on mice confirmed that repeated artificial immunization overturned the protective immune memories by promoting adaptive immune tolerance. This means that there can be risks with the continuous use of artificial immunization boosters. ²¹⁾

It has been demonstrated that that natural immunity given by healing confers longer lasting and stronger protection against future infection and symptomatic disease. ²²⁾

Current Omicron variants cause much fewer risks than Delta strains, with symptoms that generally remain in the upper respiratory tract. Currently Omicron infection is less dangerous than seasonal influenza. ²³⁾

It is becoming apparent that the excess risk of serious adverse events following artificial immunization (more then 10 people affected every 10'000), does outweight the risk reduction for COVID-19 hospitalization relative to the placebo group (less then 7 people affected every 10'000). It is recommended then that other strategies should be followed by public institutions, after carrying out a correct risk-benefit analysis. ²⁴⁾ An increased risk of autoimmune antibodies and autoinflammatory mechanisms has been found. ²⁵⁾

A high percentage of the world population has currently aquired natural immunization after encountering one or more variants of the virus, therefore it can be considered that this type of infection has become endemic like traditional flu and will be recurrent in the following years. Omicron has worked as a natural immunizer and this is helping to reach herd immunity. ²⁶⁾

Natural way for preventing severe illness are now known, first of all the fact that population can receive a sufficient level of vitamin D from the sun and/or through supplementation. ^{27) 28) 29) 30)}

Currently there is also a lot of experience in the medical community regarding correct treatment of patients. ^{31) 32) 33) 34) 35)}