A new study by one of China’s top scientists has found the ability of the new coronavirus to mutate has been vastly underestimated and different strains may account for different impacts of the disease in various parts of the world. . . The deadliest mutations in the Zhejiang patients had also been found in most patients across Europe, while the milder strains were the predominant varieties found in parts of the United States, such as Washington state, according to their paper. . .To verify the theory, Li and colleagues infected cells with strains carrying different mutations. The most aggressive strains could generate 270 times as much viral load as the weakest type. These strains also killed the cells the fastest.
https://www.msn.com/en-sg/news/world/coronavirus-mutations-affect-deadliness-of-strains-chinese-study-finds/ar-BB12Wac6
This study may help to explain the wide range of death rates see with the disease. For example, parts of Italy have seen coronavirus death rates over 0.7% based on the entire population; the death rate based on actual infections is probably several times higher. The strains from the New York area are similar to those in Italy, which may help explain the large number of deaths in New York.
On the other hand, a recent California study shows a much lower infection fatality rate:
. . .in Santa Clara County, in early April, the number of people who are or have been infected with COVID-19 is 50 to 85 times greater than the number of confirmed cases. . . the Stanford researchers wrote that their findings correspond to an infection fatality rate of 0.12% to 0.2%.
Another factor in the California results may be that there are cold viruses or other factors that generate antibodies similar to those for the COVID-19 virus, which results in false positives for the antibody tests.
If there really are different strains with much different infection fatality rates, then it may mean that areas with milder strains can reduce lockdown restrictions, while areas with the most dangerous strains may need to take more precautions.
The high mutation rate also raises troubling questions about whether a vaccine will really be effective against all strains. There is a risk that strains of coronavirus will be around even after a vaccine and become like a seasonal flu on steroids.
