Influenza, vaccines and new developments

The Influenza virus belong to the family of Orthomyxoviridae which consists of eight segments of negative-sense single-stranded RNA. The virus genome encodes 13 proteins which are: hemagglutinin (HA), neuraminidase (NA), M1 matrix protein (M1), M2 ion channel protein (M2), nuclear protein (NP), non-structural protein (NS1, NS2), and RNA polymerase complex (PB1, PB2, PA). There are five subgroups of the virus: influenza A virus; influenza B virus; influenza C virus; influenza D (Asha & Kumar, 2019). These can also be divided based on their surface glycoproteins such as HA and NA. One example is influenza A viruses which can be divided into 18 HA subtypes and 11 NA subtypes. Influenza A and B can lead to epidemics. Influenza C viruses generally cause a mild upper respiratory infection. Influenza D generally affects cattle rather than humans.

Influenza A is an enveloped, segmented, negative-strand RNA virus, belonging to the Orthomyxoviridae family. Influenza A viruses are divided into subtypes based on the proteins on the surface of the virus: hemagglutinin (HA) and neuraminidase (NA). Although its eight viral gene segments encode as many as 18 proteins there may be more (Shao et al, 2017). In fact, there are 18 different hemagglutinin subtypes and 11 different neuraminidase subtypes (Treanor, 2023). Influenza A virus is a highly infectious respiratory pathogen and is a significant threat to global public health (Shoa et al, 2017). Although identified in 1931, with attempts to develop a vaccine against the virus starting soon after the discovery, researchers still have to produce yearly vaccines. The perennial challenge is therefore to produce a one-off vaccine.