The coronavirus is currently changing slowly. There are only about two dozen mutations. There have been many reports of multiple strains of SARS-CoV-2. Virologists use the world strain as a label to the same group of samples. This does not mean they are functionally different. Strain can also refer to viral genotypes that are functionally distinct. Functional distinctness of strains requires more experimental, clinical and epidemiological data than is currently available. There is a hypothesis that there are two SARS-Cov-2 strains. These would be “D614” vs “G614”. This has not been proven. A study from China claims that people who