Coronavirus has mutated into 30 strains and ones in US are less deadlier than those in Europe, finds study
Researchers have found that there are at least 30 strains of the novel coronavirus infecting people and the deadliest mutations have been identified in patients across Europe. The milder strains were the predominant varieties found in some parts of the US such as Seattle, Washington, according to a new study.
“Despite the abundant variability of SARS-CoV-2 (the virus that causes COVID-19), one key question remains as to whether these mutations have any real functional impact on the pathogenicity of SARS-CoV-2. This is crucial in our understanding of the viral infectious mechanisms and dictates the strategy of drug and vaccine development in preparation for the next stage of the pandemic,” says the research team from China.
“To address this, we characterized 11 SARS-CoV-2 viral isolates from patients admitted to Zhejiang University-affiliated hospitals in Hangzhou, China, situated 78 km to the east of Wuhan,” says the team from the First Affiliated Hospital, Zhejiang University School of Medicine, China.
The researchers identified 33 mutations in all and found that 19 mutations were new. According to the researchers, some mutations could create strains deadlier than others. Certain strains within these patients in China were some of the most dangerous and resembled ones that spread across Europe. A separate study has found that the first confirmed COVID-19 cases of New York City were primarily from European and US sources and not Asia.
“We provide direct evidence that the SARS-CoV-2 has acquired mutations capable of substantially changing its pathogenicity. Our study provides direct evidence that mutations currently occurring in the SARS-CoV-2 genome have the functional potential to impact the viral pathogenicity,” says the team in their findings, a pre-print version of which has been published.
“A diverse collection of mutations was identified in the 11 viral isolates, including two sets of founding mutations for two major clusters of viruses currently infecting the world population. In addition, 19 identified mutations are novel, despite the relatively early sampling dates, indicating that the true diversity of the viral strains is still largely underappreciated,” they say.
The analysis shows that the most aggressive strains of SARS-CoV-2 could generate 270 times as much viral load as the least potent type. The amount of virus in the body is referred to as the viral load. However, the researchers caution that just because the mutations were milder, it does not imply that there was a low risk of death.
“Despite only 11 patient-derived isolates being analyzed in this study, we observed abundant mutational diversity, including several founding mutations for different major clusters of viruses now circulating globally. This diverse mutational spectrum is consistent with their relatively early sampling time and relative proximity to Wuhan city, where the first viral strain was identified,” say researchers.
“Similar to flu, drug and vaccine development, while urgent, need to take the impact of these accumulating mutations, especially the founding mutations, into account to avoid potential pitfalls,” the team recommends.
In a previous study, researchers from China had identified two separate strains of the new coronavirus. The research team analyzed 103 publicly available genomes from infected persons and found 70% were the more aggressive type, while the remaining 30% comprised the less aggressive type. Another study discovered three distinct strains of COVID-19, consisting of clusters of “closely related lineages” — which have been labeled ‘A’, ‘B’ and ‘C’.
Over 2,478,153 cases have been reported globally and more than 170,368 people have died in the COVID-19 pandemic as of April 21, according to the Johns Hopkins tracker.