Scientific papers mention between 8 and 33 strains of Sars-CoV-2. Recent Chinese research suggests that the ability of the virus to mutate has been underestimated. Before the second half of April 2020, most scientists said the virus was mutating slowly and the existing strains were not significantly different, so a future vaccine would be effective against all of them. Then came a study from Zhejiang University, which found dozens of new mutations.
The researchers say they have evidence that some mutations can create aggressive strains with a 270 times higher viral load (the ratio of virus particles in an infected person) than the weakest one. They used the more precise method of “ultra-deep sequencing” to map the genomes of the viral samples, but a word of caution: only 11 patients took part in the study and at the time of writing the paper had not been peer-reviewed yet.
If there are indeed more strains, does this explain different death rates in different regions? Scientists have noticed that different parts of the world had different Sars-CoV-2 strains and suspect, but have not proved yet, that varying regional death rates can be due to mutations. They also note that the novel coronavirus is an RNA virus that is likely to mutate, but the expectation is that it will become weaker over time.
Here is the current state of science on a Sparrho pinboard. NB: The pinboard contains research papers that have not been peer-reviewed yet, meaning that they have not gone through the standard scientific validation process yet.
Endre Szvetnik is Senior Editor at Sparrho. Endre works with Sparrho Heroes to curate, translate and disseminate scientific research to the wider public.