**4. RSV RNA and proteins**

The RSV genome is a single-stranded, negative-sense RNA whose length is ranging from 15,191 to 15,226 nucleotides [9]. The RSV genome contains ten genes in the order 3′-NS1-NS2-N-P-M-SH-G-F-M2-L-5′ that are transcribed sequentially into 10 independent messenger RNAs (mRNAs) (**Figure 2**). Each RSV mRNA encodes a single major protein except for M2, which encodes two separate open reading frames (ORF) for M2–1 and M2–2 proteins, respectively [9, 18–20]. The M2–1 and M2–2 ORF are located in the upstream and downstream parts of the mRNA, respectively [9]. Like many RNA viruses, RSV brings ribonucleoprotein (RNP) complex as a piece of transcriptional machinery for its genome transcription and replication inside the infected cell cytoplasm. The RNP complex consists of the viral genome, nucleoprotein (N), phosphoprotein (P), and RNA-dependent RNA polymerase [L) [21].

**Figure 2.**

*Schematic of an RSV genome. RSV genome is a negative-sense non-segmented single-stranded RNA. The genome contained 10 genes oriented from 3*′ *end: NS1, NS2, N, P, M, SH, G, F, M2 (M2–1 and M2–2), and L.*
