Researchers at the Cambridge University mapped the genome history of the SARS-CoV-2 from December to March and found three different but closely related strains of the novel coronavirus.
- Type A is the one found in bats and pangolins and has two sub-clusters, one linked to Wuhan and other is common in the United States and Australia
- Type B is derived variant from type A and is the most prevalent in Wuhan.
- Type C is descended from type B and spread to Europe.
Genome Analysis of these three strains showed that type A is the original virus that transmits to humans from bats via pangolins. But this strain was not the most common in China. Instead, type B hit the ground-zero of the pandemic.
The United States is being rocked by the original strain, type A as it is the most prevalent and recorded more than 400,000 cases of COVID-19. Two-thirds of samples in America were of type A but infected people mostly came from the West Coast.
Dr. Peter Forster and his team found that type B was most prevalent in the United Kingdom as three-quarter samples contain that strain. Germany France, Belgium, Switzerland, and the Netherlands were also bombarded by type B. Another distinct variant, type C is the daughter of type B and spread to Europe via Singapore. Researchers believe the novel coronavirus is mutating constantly to overcome the immune resistance in different populations.
The study has revealed the oddity that original strain, type A spread through West Coast despite not being the most common in China, type B. However both the variants were in existence by January when America confirmed its first case, doesn’t mean it arrived earlier and was not detected. The researchers say the study was too small for drawing any firm conclusions. The published work only traced the samples of 160 infected patients across the world, including the majority of the first cases in the United States and Europe.
Methods used for tracing the prehistoric ancient humans’ migration were adapted for tracking the novel coronavirus spread. The team of researchers has recently updated the analysis for including more than the thousand cases of COVID-19 for providing a clearer snapshot. It has not been peer-reviewed.
The findings of the research are published in the journal PNAS, which initially suggested that type C was the most prevalent in Europe.
The recent data shows that variant B is spreading more vigorously, all but one of the thirty-one samples taken from novel coronavirus patients in Switzerland belonged to the second cluster. It comes after the findings of two genetic studies revealed that most of the outbreak in New York came from Europe and infection was spread in the mid of February, weeks before they city confirmed its first case.
Researchers at Ichan School of Medicine at Mount Sinai NYU studied the DNA from hundreds of samples of novel coronavirus patients for concluding that travelers from Europe brought the SARS-CoV-2 to the Big Apple.
The finding of Dr. Forster and his team suggests that the variant of the virus that arrived in Washington has originally come from China. The Cambridge researchers found that two-thirds of the 310 samples of COVID-19 patients, sequenced in the United States were of type A.
All of the cases linked to cruise ships in the United States had the strains of type B. It is still not clear that on what ships they caught the novel coronavirus but the Diamond Princess which is quarantined off the Japan coast for weeks, recorded more than seven hundred cases.