-Influenza viruses can be distinguished based on the glycoprotein in their surface and their reactions to certain antibodies
-Influenza viruses A, B, and C, can differ in their host range, variability of genome and morphology (Rapid, 2012).
-contains eight segments of negative single stranded RNA in helical molecules called caspids (Bauman, 2014). There is approximately 500 spike-like projections in influenza virus’s virion; the HA glycoprotein resemble a rod-like projection and the NA resemble a mushroom-like projection (Rapid, 2012).
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-Influenza viruses are restricted in the epithelial cells of respiratory tract because the lack of certain proteins needed for growth in the rest of the body.
-They attach to host cell, take over their metabolic machinery to reproduce, and eventually results in host cell death when they burst through membrane to continue growth (Bauman, 2014). -Influenza viruses range about 80 to 120 nanometers in diameter, are roughly spherical, and some are able to alter their shape and size depending on their environment (Rapid, 2012). -Influenza viruses do not have a cytoplasmic membrane, instead they are composed of a lipid envelope with the glycoprotein spikes (HA and NA) projecting out of envelope which function to attach to host cell -The eight single-stranded RNA within the caspids are held together through disulfide bonds and are divided into nucleotide segments, each synthesizing amino acids, or genes, which eventually form complexes that promote viral growth and reproduction (Rapid, 2012). -Antigens can change over time thus causing vaccines to be ineffective. |