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The effect of influenza virus was severe to the extent where average life span in US was depressed by a period of 10 years.
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What was the effect of the influenza virus that developed in the us in 1918-?
the virus spred around the world and killed millions of people
What was the effect of the infuenza virus that developed in the US in 1918?
The virus spread around the world and killed millions of people
What year did the influenza virus claim its greatest number of victims in the US?
in 1918.
Are there two types of influenza vaccines licensed in the us?
Yes, there are two main types of influenza vaccines licensed in the U.S.: inactivated influenza vaccines (IIVs), which are made from killed virus, and live attenuated influenza vaccines (LAIVs), which contain weakened virus. IIVs are typically given as an injection, while LAIVs are administered as a nasal spray. Both types aim to provide immunity against the most common strains of the influenza virus. Additionally, there are variations within these categories, including high-dose and recombinant options.
What is the correct classification for a licensed vaccine that contains a non-infectious form of the H1N1 flu virus?
LAIV - Live Attenuated Influenza Vaccine for Type A H1N1/09 influenza. In the US, you could add that it is FDA Approved (Food and Drug Administration, the US licensing agent for prescription drugs.)
What is the World Health Organization's definition of health?
World Health Organization Definition of Pandemic:"An influenza pandemic occurs with the appearance of a new influenza virus against which none of us has any immunity. This results in several, simultaneous epidemics worldwide with high numbers of cases and deaths. With the increase in global transport and communications, as well as urbanization and overcrowded conditions, epidemics due to the new influenza virus are likely to be established quickly around the world."
What is the difference between H1N1 H1N2 H3N2 and H3N1 viruses?
Overview:H1N1, H1N2, and H3N2 are the only known Influenza A virus subtypes currently circulating among humans. All the subtypes listed in the question, i.e., H1N1, H1N2, H3N1 and H3N2 are the known subtypes of influenza A viruses that are endemic in pigs and create influenza in pigs, from which reassortants have formed new strains that can be infective to humans. H1N1 is the "swine flu" subtype of influenza, of which there are several different strains. This subtype is usually seen in humans and pigs. The better known reassortant H1N1 virus strain currently circulating is H1N1/09, the pandemic swine flu virus that caused the pandemic of 2009 and infected humans, pigs, birds, ferrets, dogs, and cats during the pandemic. There are several other less well known strains of the H1N1 subtype.H1N2 is a common flu in pigs in the Upper Midwest of the US. Until 2011, only one case had been known to occur in humans and that was in 2007 in Michigan. The second ever known case was found in an infant in December 2011 in Minnesota.H3N1 mostly only infects pigs.H3N2 is the subtype that produced a strain of flu that caused the Hong Kong Flu and another was the cause of the Fujian Flu, etc. In birds, humans, and pigs, there have been many new strains mutated and this subtype is becoming more prevalent in seasonal influenza.For background, the meanings of "H" and "N" in the nomenclature:Hemagglutinin: An important surface protein on the capsid (coat) of the influenza virus that is essential for the reproduction and the spread of the virus in the body in the lytic cycle of virus replication. This protein enables the virus to attach itself to a cell in the respiratory system or other mucous tissue and penetrate it to invade and use the host cell for reproduction. Referred to as the "H" in influenza viruses.Neuraminidase: An important surface structure protein of the influenza virus that is an essential enzyme for the spread of the virus throughout the respiratory tract. It enables the virus to escape the host cell and infect new cells. Referred to as the "N" in influenza viruses.See more about the lytic cycle and influenza virus nomenclature in the related questions below.Types of Influenza VirusesThere are three types of influenza viruses: Types A, B and C. Influenza A and B viruses cause seasonal outbreaks and epidemics of influenza virus infections each flu season. Type A causes all pandemics. Influenza type C infections cause a mild respiratory illness and are not thought to cause epidemics. Influenza A viruses are divided into subtypes based on the configuration of the two proteins on the surface of the viruses: hemagglutinin (H) and neuraminidase (N). [Not all H1N1 viruses are the same; not all H5N1 viruses are the same.....etc] There are 16 different hemagglutinin subtypes and 9 different neuraminidase subtypes. Influenza A viruses can be further broken down into different strains.Influenza B viruses are not divided into subtypes. Influenza B viruses also can be further broken down into different strains.Influenza A (H1N1), A (H3N2), and influenza B strains are included in each year's influenza vaccine. Getting a flu vaccination can protect against influenza A and B viruses. The flu vaccine does not protect against influenza C viruses.More information including how influenza viruses change: Drift and ShiftInfluenza viruses are dynamic and are continuously mutating, reassorting, and evolving. Influenza viruses can change in two different ways: antigenic drift and antigenic shift. Influenza viruses are changing by antigenic drift all the time, but antigenic shift happens only occasionally. Influenza type A viruses undergo both kinds of changes; influenza type B viruses change only by the more gradual process of antigenic drift. Antigenic drift refers to small, gradual changes that occur through point mutations in the two genes that contain the genetic material to produce the main surface proteins, hemagglutinin, and neuraminidase. These point mutations occur unpredictably and result in minor changes to these surface proteins. Antigenic drift produces new virus strains that may not be recognized by antibodies produced after exposure to earlier influenza strains.This process works as follows: a person infected with a particular influenza virus strain develops antibodies against that strain. As newer virus strains appear, the antibodies against the older strains might not recognize the "newer" virus to inactivate it, and infection with a new strain can occur. This is one of the main reasons why people can become infected with influenza viruses more than one time and why global surveillance is critical in order to monitor the evolution of human influenza virus stains for selection of which strains should be included in the annual production of influenza vaccine.In most years, one or two of the three virus strains in the seasonal influenza vaccine are updated to keep up with the changes in the circulating influenza viruses. For this reason, people who want to be immunized against influenza need to be vaccinated every year.Antigenic shift refers to an abrupt, major change to produce a novel influenza A virus subtype in humans that had not been currently circulating among people (see more information below under Influenza Type A and Its Subtypes).Antigenic shift can occur either through direct animal (poultry)-to-human transmission or through mixing of human influenza A and animal influenza A virus genes to create a new human influenza A subtype virus through a process called genetic reassortment or reassortant. Antigenic shift results in a new human influenza A subtype.A global influenza pandemic (worldwide spread) may occur if three conditions are met:A new subtype of influenza A virus is introduced into the human population.The virus causes serious illness in humans.The virus can spread easily from person to person in a sustained manner.
Where was the 1957 flu pandemic located Or where did it start?
The "Asian Flu" was a category 2 flu pandemic outbreak of avian influenza that originated in China in early 1956 lasting until 1958. It originated from mutation in wild ducks combining with a pre-existing human strain. The virus was first identified in Guizhou. It spread to Singapore in February 1957, reached Hong Kong by April, and US by June. Death toll in the US was approximately 69,800. Estimates of worldwide deaths caused by this pandemic varies widely depending on source; ranging from 1 million to 4 million, with WHO settling on "about 2 million". Asian Flu was of the H2N2 subtype (a notation that refers to the configuration of the hemagglutinin and neuraminidase proteins in the virus) of type A influenza, and an influenza vaccine was developed in 1957 to contain its outbreak. The Asian Flu strain later evolved via antigenic shift into H3N2 which caused a milder pandemic from 1968 to 1969. Both the H2N2 and H3N2 pandemic strains contained avian influenza virus RNA segments. "While the pandemic human influenza viruses of 1957 (H2N2) and 1968 (H3N2) clearly arose through reassortment between human and avian viruses, the influenza virus causing the 'Spanish flu' in 1918 appears to be entirely derived from an avian source (Belshe 2005)."
What antigens will be in the 2010-2011 seasonal flu vaccine?
According to the Centers for Disease Control and Prevention: The flu vaccine protects against the three main flu strains that research indicates will cause the most illness during the flu season. This year's influenza vaccine contains three new influenza virus strains. They are: * A/California/7/2009 (H1N1)-like virus (the same strain as was used for 2009 H1N1 monovalent vaccines); * A/Perth/16/2009 (H3N2)-like virus; * B/Brisbane 60/2008-like antigens. The 2010-11 influenza vaccine can protect you from getting sick from these three viruses, or it can make your illness milder if you get a related but different influenza virus strain. The strain of H1N1 influenza included in the 2010-2011 seasonal flu vaccine in the US is the same that caused the H1N1 Pandemic "Swine" Flu in 2009. A separate vaccination for that will not be required this year.
When and where do scientists believe influenza started?
There have been many influenza epidemics. There are now two well-known pandemics (covers a much larger world-wide area than an epidemic or a smaller outbreak). The "Spanish Flu" pandemic was in 1918 and 50-70 million people died of the virus. The most recent pandemic was the H1N1/09 "Swine Flu" pandemic beginning in 2009 with some isolated cases still ongoing in 2012.
Which operation may be turned on in the body if you contract the influenza virus?
In those with healthy immune systems, the exposure to the virus causing the flu will trigger an immune response. This is how our bodies disable the virus so it can not continue to infect us. See the related question in the related questions section for more information on how the immune system works in these situations.
How do you know you have flu A?
There are rapid field tests for influenza A that can be used by doctors to confirm the presence of an infection by a Type A influenza virus in a matter of minutes. Medical professionals rely on evaluation of symptoms and history of exposure as well as known presence of the disease in the community more often than laboratory testing. If there is a need to know that you have a specific flu virus, such as swine flu or avian flu, there are a few labs, like those at the US Centers for Disease Control and Prevention (CDC) that can perform those types of lab studies. Usually that is not necessary since most all forms of the influenza virus are treated the same way.
