abstract background novel coronavirus 2019-ncov. virus covid 19-ncp. coronavirus ncov denoted is single-stranded rna virus

19ncp 2019ncov abstract background bacterial bacterium biology cell china chinese concept contagious corona coronavirus covid covid19 danger denoted diagnosis disease distancing epidemic fever flu health human illness illustration infect infection infectious influenza medical medicine microbe microbiology ncov novel outbreak pandemic pathogen physical pneumonia rna sars science sick sickness sign singlestranded symptoms syndrome vaccine vector viral virology virus warning wuhan yellow