The number of coronavirus strains is growing rapidly. So much so that the scale of the mutation poses a threat to the development of new treatments and diagnostics for COVID-19. This is the conclusion reached by American scientists in a new study.

The rate of change of the SARS-CoV-2 virus could lead to undiagnosed strains that will limit the effectiveness of vaccines, treatments and diagnostic tests for COVID-19.

“While there were only about 10 dominant strains of the virus worldwide in April 2020, by the spring of 2021 their number had reached 100 mutations,” explains Dr. Christina Ramirez, professor of biostatistics at the University of California, Los Angeles. She is also the lead author of a study that looked at mutations in SARS-CoV-2 RNA sequences isolated between January 2020 and March 2021.

The results of an international team of scientists are published in the June issue of the peer-reviewed journal EMBO Molecular Medicine.

Given how much remains unknown about the new type of coronavirus, as well as the risk of further mutations and variants of the virus, the authors of the work said that public health agencies should allocate resources for in-depth research on mutations across the SARS-CoV-2 genome, its replication functions and various virus proteins.

Dr. Harold Burger, study co-author and infectious disease physician at the University of California, Davis, added that “ideally, molecular sequencing should include viruses from asymptomatic and moderately ill people of all ages, in addition to samples from sicker patients. Asymptomatic people can pass the virus on to others. The extent of the disease is a consequence of the patient’s condition, not just the function of the virus. This approach will provide valuable insight into the evolution and spread of the epidemic. ”

In their study, the scientists analyzed the complete SARS-CoV-2 genome sequences with known sampling dates, which were downloaded from GISAID. For the selected time period, all complete date-sampled sequences from each country were included. The sequences were combined according to the sampling date.