The Virus

SARS-CoV2
SARS-CoV2 is an RNA virus which causes the disease COVID-19. Although SARS-CoV2 is a new virus it actually belongs to the group of common cold Human coronaviruses (CoVs). “Coronavirus” is a generic term that includes a large family of viruses.

Actually there are multiple types of coronaviruses, some of which commonly cause mild upper-respiratory tract illnesses. Common cold coronaviruses are ubiquitous; wherever investigators have looked, they have been detected. Their seasonality depends, in part, on the climate.
Since there are many coronavirus types every newly detected virus receives a specific name. In COVID-19, ‘CO’ stands for ‘corona,’ ‘VI’ for ‘virus,’ ‘D’ for disease and 19 indicates the year it was discovered.
SARS-CoV2 stands for Severe Acute Respiratory Syndrome CoronaVirus 2 and is actually the virus that causes COVID-19 (the disease). Although SARS-CoV2 has genetic similarities to SARS-CoV, the virus that caused an outbreak of severe acute respiratory syndrome (SARS) in 2002-2003 it is not the same virus.

Like many other DNA and RNA viruses coronaviruses appear to be an ancient viral lineage and there seems to be an ancient coevolutionary relationship between coronaviruses and their natural hosts.
Until today there have been seven coronavirus types which have been associated with diseases in humans. The first one was already discovered in the 1960s.
Studies linked them to as much as one-third of upper respiratory tract infections during winter outbreaks. SARS has been discovered in 2002.

SARS-CoV-2, is an RNA virus, which are more prone to changes and mutations compared with DNA viruses like smallpox. So, as it has been passing from person to person over the past months, it has been, and continues to be, mutating. Mutation rate drives viral evolution and genome variability, thereby enabling viruses to escape host immunity and to develop drug resistance.
RNA viruses are characterized by a high mutation rate, up to a million times higher than that of their hosts. The virus is evolving and European, North American and Asian strains might coexist, each of them characterized by a different mutation pattern.

Over many years there have been six coronavirus serotypes associated with disease in humans: HCoV-229E, HCoV-NL63, HCoV-OC43, HCoV-HKU1, SARS-CoV, SARS-CoV-2, and MERS-CoV. Since our bodies had to deal with different coronaviruses in the past, it appears that most people already have a congenital or general immunity to e.g. influenza and other viruses.

A study in the journal Cell shows that most people neutralize the coronavirus by mucosal and cellular immunity (T-cells), while experiencing few or no symptoms. A study detected SARS-CoV-2-reactive CD4+ T cells in ∼40%–60% of unexposed individuals, suggesting cross-reactive T cell recognition between circulating “common cold” coronaviruses and SARS-CoV-2.

Most people therefore already have a congenital or cross-immunity because they were already in contact with variants of the same virus.
That is probably one of the causes why most people who test positive (PCR) have no complaints. Their immune system is strong enough. So strengthening natural immunity is a very logical and healthy approach.

SARS-CoV-2 Vermehrungszyklus (German)