Washington, Sep 24 : Robert Redfield, Director of the US Centers for Disease Control and Prevention (CDC), has said that a majority of Americans remain susceptible to the novel coronavirus. "CDC is in the process of a very large, sequential study across the entire US, measuring serology," Redfield told the Senate Health Committee during a hearing on Wednesday. "The preliminary results on the first round show that a majority of our nation - more than 90 per cent of the population - remains susceptible," Xinhua news agency quoted the CDC chief as saying. "It varies in different geographic parts from states, But it does show that a majority of Americans are still susceptible to this virus," he added. The remarks came a day after the Covid-19 death toll in the US surpassed th 200,000 mark. Currently, the US is the worst-hit country with the world's highest number of cases and deaths at 6,943,071 and 201,957. Anthony Fauci, director of the US National Institute of Allergy and Infectious Disease, also attended Wednesday's hearing and warned of the long-term effects that disease might have on those infected. Fauci noted that a recent study in non-athletes who have recovered from the virus showed that in their MRIs "they found that about 60 to 70 per cent of them had indication of inflammatory disease in the heart". "They could wind up when you have inflammation, you could have scarring, that could lead to arrhythmias later on, or that could lead to cardiomyopathies," he said. "It's something we really need to keep our eye out on." Stephen Hahn, commissioner of the US Food and Drug Administration, and Brett Giroir, assistant secretary for health at the Department of Health and Human Services, also testified at the hearing. President Donald Trump has called the country hitting 200,000 coronavirus deaths "a shame". He has also sought to defend his administration's response to the pandemic, which has been under sharp criticism. /IANS