This diagram shows how different flu viruses exchange genetic material in a process known as antigenic shift national institute of allergy and infectious diseases (niaid) antigenic shift influenza virus influenza a virus just as natural selection has shaped the evolution of humans, plants, and all living things on the planet,. There are three types of influenza viruses: a, b and c human influenza a and b viruses cause seasonal epidemics of disease almost every winter the emergence of new and very different influenza virus strains can infect higher than normal levels of people which may cause an influenza pandemic influenza type c. The flu is a highly contagious and common illness that is caused by the influenza virus there are three different types of flu viruses: influenza a, b, and c—all of which cause illness in humans people can get the flu any time of year, but in the united states and most of the northern hemisphere, flu season. As the appearance of the new subtype is paralleled by the disappearance of the old subtype, it is unlikely that the dual infection was by 2 human influenza a subtypes however, influenza a viruses infect other species of animals, such as horses and birds it was postulated that dual infection with human and animal or bird. A segmented genome enables antigenic shift, in which an influenza a virus strain acquires the ha segment, and possibly the na segment as well, from an influenza virus of a different subtype this segment reassortment can happen in cells infected with different human and animal viruses, and the resulting. Comparative sequence analysis on different strains of swine influenza virus sub-type h1n1 for neuraminidase and hemagglutinin deepak kumar sharma, anil kumar rawat, shipra srivastava, rajeev srivastava and ajay kumar 1 department of biotechnology, institute of biomedical education and research,. When these viruses cross different species, that creates conditions ripe for another pandemic, as people lack immunity to these new strains so what are the new strains that are emerging from animals, threatening explosive epidemics advertisement comparison of flu strains - h1nwhat to help me.
The histopathology of fatal influenza virus pneumonias as documented over the past 120 years is reviewed here strikingly, the spectrum of pathologic changes described in the 1918 influenza pandemic is not significantly different from the histopathology observed in other less lethal pandemics or even in deaths occurring. In late 2002, outbreaks of highly pathogenic h5n1 avian influenza were reported in 10 countries in asia and human cases were reported in vietnam and thailand 233,234 since then, h5n1 viruses have spread to other countries in asia, europe , and africa, and more than 500 cases of human infection and more than 300. While only two influenza a subtypes currently circulate in humans, influenza a viruses of all subtypes can infect birds of particular concern to public health authorities is the highly pathogenic avian influenza a(h5n1) virus (“bird flu”) which causes devastating disease in. What causes the flu how is it different from a cold the flu is a viral infection caused by the influenza virus, a respiratory virus the common cold is also a viral infection caused by the adenovirus or coronavirus and there are many, many subsets with a lot of variability that's why it's said there's no cure for.
Influenza infects many animal species, and transfer of viral strains between species can occur birds are thought to be the main animal reservoirs of influenza viruses sixteen forms of hemagglutinin and nine forms of neuraminidase have been identified all known subtypes (hxny) are found in. Host-established immunity moreover, because the influenza virus genome consists of discrete rna segments, genetic re-assortment can occur easily when two different influenza viruses co-infect the same host  both antigenic drift and shift are very important strategies for the influenza viral evolution. The hemagglutinin glycoprotein is the primary target of antibodies that confer protective immunity to influenza viruses antibodies to other influenza proteins likely act in: fc-receptor mediated uptake of virus particles, antibody-dependent cell cytotoxicity, delay of replication kinetics and, in aggregate, they.
They proposed that the low incidence of severe h5n1 infections in elderly people compared with that in younger people might be related to the presence of cross- protective antibodies to neuraminidase that had been induced by seasonal influenza a h1n1 viruses there is another type of cross-reactive. Influenza viruses are categorized by the glycoprotein spikes on their surface – the 'ha' or haemagglutinin protein (16 different subtypes identified so far) and the 'na' or neuraminidase protein (nine subtypes) all 16 ha and nine na subtypes ( see box on terminology) have been detected in various combinations in aquatic. Reassortment patterns of avian influenza virus internal segments among different subtypes lu lu, samantha j lycett and andrew j leigh brownemail author bmc evolutionary biology201414:16 © lu et al licensee biomed central ltd 2014 received: 9 october 2013.
Our data suggest that the receptor-binding site of contemporary h7 influenza viruses in aquatic and terrestrial birds was formed after the introduction of their common precursor from ducks to a new host, presumably, gallinaceous poultry the uniformity of the receptor-binding profile of h7 influenza viruses in various wild and. Vaccine antigens possessing k160 ha and t160 ha elicit different responses in humans donors were vaccinated with seasonal influenza vaccines, and sera were collected before and 28 d after vaccination frnts were completed using viruses that possessed t160 ha or k160 ha (a) flublok induced.
H1n1 flu is a variety of influenza a h1n1 indicates the viral serotype it's a kind of shorthand for characteristics that identify the virus to your immune system and allow the virus to enter your cells there are many different strains of h1n1 flu each year's flu vaccine includes varieties of influenza a — both h1n1 and h3n2. There are four different types of influenza virus, three of which infect people of those three, influenza a and b are the most common and each of those subsets develops different strains h1n1 and h3n2, for example, are strains of influenza a, and they adapt by constantly changing their surface proteins. Novel and variant influenza a viruses flu viruses constantly change and mutate novel and variant influenza a viruses can infect and cause severe respiratory illness in humans these influenza viruses are different from currently circulating human influenza a virus subtypes and include influenza viruses from.