Despite being three years into the Covid-19 pandemic and hundreds of millions of diagnoses, some people appear to have never tested positive for the virus. NBC News’ medical reporter Erika Edwards breaks down whether it’s possible for some people to…

A new Covid-19 subvariant is rapidly spreading across the country, accounting for at least 43 percent of confirmed cases over the past week, according to the CDC. NBC News’ medical contributor Dr. Kavita Patel explains whether another surge of cases…