Intranasal DNA Vaccine for Protection against Respiratory Infectious Diseases: The Delivery Perspectives

Xu, Yingying; Yuen, Pak-Wai; Lam, Jenny Ka-Wing

Respiratory syncytial virus (RSV) is a single stranded RNA pneumovirus which belongs to Paramyxoviridae family. It accounts for one of the leading pathogeneses of lower respiratory tract infections and hospitalization in infants and young children [102] , as well as the elderly and high-risk population [103] . Immunity against RSV is dependent on the induction of antibody responses. In addition, CD8 + T cells responses have been shown to reduce disease severity [104] . Although maternal antibodies appear to protect infants against infection, their amount gradually decreases within the first few months of life. Human RSV lacks an approved vaccine or an antiviral therapy. To prevent infant and childhood infection, vaccine should be able to induce immune responses rapidly after birth. This could be a challenging task because the immune system at the first few months of life is immature, and the persistence of maternal antibodies may limit the induction of infant antibodies responses. Three RSV proteins, namely the fusion (F) protein, attachment glycoprotein (G) and matrix protein (M2), are the leading candidates for RSV vaccine development [105] [106] [107] [108] [109] [110] [111] .