Characterization Of Duck Viperin And The Natural Reservoir Of Influenza A Virus ( Iav ) Essay

Every year, millions of people start talking about the influenza virus and getting their vaccines as the flu season approaches, which starts around the October-November period and reaches its peak between December and March. Therefore, public health officials around the world- and in the U.S in particular- are constantly challenged by properly preparing for the annual influenza dilemma, given that this viruses, and other respiratory viruses, are a serious health threat to the U.S population and the world as a whole. Furthermore, what makes the influenza virus even more challenging to control is that it can mutate rapidly and reassort to form new strains, having the ability to reside in multiple animal hosts. In fact, many scientists and researchers have been doing in-depth intensive research so as to understand the mechanism behind this unique characteristic of the virus, try to find new ways to control it, and explore different areas of protection and vaccination.

Influenza, an innocent little virus that annually comes and goes, has always been a part of people’s lives. Knowing this, one would not believe that it has caused not one, not two, but three pandemics and is on its way to causing a fourth! The Spanish flu of 1918, the Asian flu of 1957, and the Hong Kong

The seasonal influenza vaccine has been in existence for a numerous amount of decades, therefore so has the gradual implementation of the vaccination. Through recent studies, the break through knowledge of the importance of enforcing the requirement of this vaccine for children has acquired increasing acceptance statistics. During the many outbreaks of different classified strands of avian influenza, the health care community has been unable to retain the virus and alleviate patients efficiently. However current tallies have shown that the system for controlling these outbreaks have improved lowering the mortality rate profoundly. (BioScience Trends, 2013).

Influenza remains as a significant global threat to public health. In United States alone, a typical influenza epidemic results in over 25 million infections, 300,000 hospitalizations and 13,000 deaths every year (1). The virus evolves antigenically from one year to the next, requiring annual reformulation of the vaccine and leading to variable vaccine efficacy. Exacerbating this natural antigenic evolution, adaptation to the chicken eggs may occur during the manufacture of virus used to produce the inactivated vaccine (2). This year such adaptation has reduced the vaccine efficacy against H3N2 strain (3). Low vaccine efficacy is expected to generate higher attack rates, as has already occured in Australia (3, 4). Compounding the effects of low vaccine efficacy, public perception following the widespread media attention may depress vaccine uptake for a given year. The combination of low vaccine efficacy and low coverage has the potential to reduce herd immunity, putting the population at risk of elevated infection incidence and ultimately high rates of infections and mortality. Consequently, optimizing epidemiological effectiveness of vaccination given vaccine efficacy is imperative to minimize the annual mortality and morbidity of influenza.

Describe two innate (nonspecific) immune responses that might prevent an influenza virus from causing any noticeable infection, even if the virus enters your respiratory passages.

Wild aquatic fowl, ducks in particular, serve as a reservoir for the Influenza virus to transmit into poultry and then to humans. Infected birds shed flu viruses in their saliva, nasal secretions, and feces (CDC, 2004). The current virus seen in Asia is denoted as H5N1 and was first seen in terns in South Africa in 1961 (CDC, 2004). The first human seen infection of the avian H5N1 viruses was in 1997 in Hong Kong in a three- year old boy (Ruben, 2005). The outbreak involved 18 cases and killed 6, one third of the confirmed infected population (Rueben, 2005). In three days 1.5 million birds were killed in order to prevent further spread. A new pandemic is now on the horizon with recent outbreaks in poultry in the eight Asian countries of Cambodia, China, Indonesia, Japan, Laos, South Korea, Thailand, and Vietnam since 2004 (CDC, 2005). As of July 5, 2005, there have been 108 reported human cases of the H5N1 virus with 54 deaths (CDC, 2004). In wake of a

Once there was a virus named Birdie. This virus was a Bird Flu, or Avian Influenza, virus of the subtype H5N1, the first strain of Avian Influenza having the ability to infect humans (Normandin and Solan). Birdie looked like a microscopic pomander, a fragrant orange with cloves stuck in it. Inside, she had eight pieces of single stranded ribonucleic acid or ssRNA. Birdie was deadly to humans, but was not able to spread from one human to another. She could only spread from birds to humans ("Bird Flu"). Birdie started out inside a chicken named Cluck, where she was formed. A little while later, Cluck's farmer Mark, sold his Cluck, to Joe, another poultry farmer because Mark did not realize that Cluck had H5N1. After a few months of Cluck living

It provides evidence that human monoclonal antibodies can neutralize, or inhibit the effect of a broad range of IFV A and B. The study followed the natural immune responses of recently discovered broadly neutralizing antibodies (bnAb) on the stem and head regions of IFV A surface protein, Haemagglutinin (HA). Dr. Brandenburg and colleagues were particularly interested in studying the ability of the stem and head binding bnAb to intervene during attachment and fusion, disrupt protein cleavage and contain newly synthesized viruses within the cell at the different stages of the virus’s

Influenza A is compromised of two proteins named Hemagglutinin (H protein) and Neuraminidase (N protein), which are part of a single RDA genome. Due to how weak and small the virus is, it lacks the immunity to warm, tropical climates and thrives in cold, dry climates. Thus, during the colder months of the year populations expect a strain of flu to break out. While a vaccine for the flu developed in 1967 and revised in 1978, 1990 and 2003, influenza vaccines must be changed annually to cover any recently emerged strains due to how often it

IAV is a virus classified as part of the orthomyxoviridae and one of the causative agents of influenza or “the flu”. (Edinger, Pohl & Stertz, 2014) Its natural reservoir is primarily wild aquatic fowl where it is mostly nonpathogenic, though zoonotic infections can occur in mammals and domestic fowl. (Klenk, Matrosovich & Stech, 2008) The jump between species often results in the establishment of highly pathogenic variants that can have devastating effects, as was the case of the “Spanish” influenza pandemic of 1918. (Taubenberger, 2006) The infection across special barriers is dependent on changes to the structure of glycoproteins on the viral envelope, particularly haemagglutinin (HA). The different subtypes of HA and neuraminidase (NA) serve to classify different viral lineages. These changes in the structure can result in proteolytic activation; that when coupled to changes of receptor binding specificity allow for interspecies transmission. (Klenk, Matrosovich & Stech, 2008) The modifications can affect the pathogenicity of the virus even within the same species, which can allow for infection of new cell types, or even systemic disease. (Steinhauer, 1999) These mutations accumulate through successive replications or genetic re-assortment during confection. The resulting structural changes account for the observed antigenic drift that causes loss of immunity despite prior exposures to the virus. This evolutionary process drives the consistent

The Influenza virus seems to be very difficult to deal with in general due to its mutation which makes it require different flu vaccines annually. Considering the fact that it contains eight different RNA strands covered by a lipid layer as stated. Having your test come out false negative shows how tricky this virus could

Influenza A viruses are very diverse, and two viruses that share a subtype may be only distantly related. The high variability is the result of two processes, mutation and genetic reassortment (Fenner et al., 1987) 79. These viruses lack a proofreading and error correction mechanism during replication, therefore small, constant genetic changes occur due to point mutation, deletion, or substitution, which can result in new mutants (CDC, 2005; Escorcia et al. 2008). In case selective pressures (such as neutralizing antibodies, suboptimal receptor binding or chemical antivirals) are acting during viral replication on a host or population scale, mutants with corresponding selective advantages(e.g. escape from neutralisation, reshaped receptor-binding

On paper the avian flu may seem like the flu strains that we experience every year, but H5N1 is certainly unique. The first reason for this is that research has suggested that for currently idiopathic reasons the avian flu seems to have a predisposition to mutation, enabling it to rapidly create new strains that may be more dangerous, more contagious, or even resistant to antibiotics (which has already been observed in at least one case of an infected Vietnamese teenager). The reason avian flu has not yet caused any major outbreaks is because right now the virus is unable to be transmitted from human to human, only from bird to bird or bird to human. With such a high tendency to mutate, it is only a matter of time before the avian flu mutates into a strain that can be transmitted between

As already mentioned, the H5.N1 is a subtype of an influenza A type. This type consists of RNA. This RNA names as HA and NA. The HA is glycoproteins found on the surface of the virus. This special protein helps the virus to bind to the host cell. While NA is glycosylated enzyme sits on the surface as well. It helps to release the virus from the host cell. In reality, the least pathogenic virus is H5.N1 or (LPAI H5N1), is commonly happening in wild birds for example, in 1983 it is reported that the virus being carried by the ring-billed gulls in Pennsylvania, ( Bird flu (H5.N1) Genetic in news-medical). The virus itself cannot be pathogenic unless some changes occur, which means new progeny. When the RNA of two viruses enters a combination process in the host cell.

The DF-1 cell line is often used in the research of avian viruses. It is unique to the group of mammalian cell lines in that it does not contain endogenous sequences linked to avian sarcoma and leukosis, a first of its kind in continuous avian cell lines. The study of avian retrovirology relies heavily on access to a continuous cell line, and the DF-1 cell line is both continuous and non-transformed. Because the cell line lacks any sequences related to avian viruses, it is most popularly used to study the effects of these viruses on cells as they