We're both relying on what other people say. I'm going to use your own metric here, your own standard, that only people who are qualified virologists are capable of knowing whether the virus exists. The number of people worldwide who are suitably qualified and are working in public health, institutes and labs that study viruses, pharmaceutical firms who are studying the virus to come up with treatments and so on will number several thousand people.
Every single one of these qualified people say that the virus exists. Every single one of them. You can't point to a single qualified person who has hands on experience of the virus who says that it doesn't exist. Not a single solitary person.