The SARS-CoV-2 variants around us: A literature review

The SARS-CoV-2 outbreak in Wuhan (China) has become a global pandemic. Various variants of SARS-CoV-2 have been detected and the variant number of the virus continues to grow. A particular SARS-CoV-2 variant can be detected in a country that was never infected before by the virus. Furthermore, a specific SARS-CoV-2 variant, which has been detected before in a country, can be detected too in another country. The emergence of SARS-CoV-2 variants is mainly caused by mutations and recombinations. The emergence of a SARS-CoV-2 variant in a country (which was never infected before by the virus), of course, can be explained easily as it is caused by the effect of the viral spread among countries, although there may be another explanation. On the other hand, the emergence of a SARS-CoV-2 variant (which has been previously detected in a country) in another country, always has been explained only as it is caused by the effect of the viral spread between countries. However, maybe it is caused by another factor. A literature review was performed to look for the explanation related to the emergence of a certain SARS-Cov-2 variant (which is already detected before in another country) in a country. Based on the literature review results related to the RNA virus genome and its mutation as well as its recombination, it is easy to explain the cause/agent of the emergence of a SARS-CoV-2 variant (which has been previously detected elsewhere) in another country. In this case, the emergence of a SARS-CoV-2 variant (which has been previously detected elsewhere) in a country may be caused by mutations and/or recombinations in addition to the probability that it may also occur due to the spread of the virus among countries; so the emergence of SARS-CoV-2 variant that has been previously detected elsewhere in other countries does not only occur due to the spread of the virus.