Influenza Virus Molecule

Influenza Virus Strain

Subype
H1N1 A/Albany/12/1951 A/Beijing/22808/2009 A/Beijing/262/1995
A/Brevig Mission/1/1918 A/Brisbane/59/2007 A/California/04/2009
A/California/06/2009 A/California/07/2009 A/Chile/1/1983
A/England/195/2009 A/England/42/1972 A/New Caledonia/20/1999
A/New York/06/2009 A/New York/1/1918 A/New York/18/2009
A/NewJersey/8/1976 A/Ohio/07/2009 A/Ohio/UR06-0091/2007
A/Puerto Rico/8/1934 A/Puerto Rico/8/34/Mount Sinai A/Solomon Islands/3/2006
A/swine/Belgium/1/1998 A/Swine/Wisconsin/136/1997 A/Taiwan/01/1986
A/Texas/05/2009 A/Texas/36/1991 A/USSR/90/1977
A/USSR/92/1977 A/WSN/1933  
H1N2 A/swine/Guangxi/13/2006    
H1N3 A/duck/NZL/160/1976    
H1N8 A/Egyptian goose/South Africa/AI1448/2007    
H1N9 A/mallard/Ohio/265/1987    
H2N2 A/Ann Arbor/6/1960 A/Canada/720/2005 A/Japan/305/1957
A/Guiyang/1/1957    
H2N3 A/swine/Missouri/4296424/2006    
H2N8 A/herring gull/DE/703/1988    
H3N1 A/swine/Korea/PZ72-1/2006    
H3N2 A/Aichi/2/1968 A/Babol/36/2005 A/Brisbane/10/2007
A/California/7/2004 A/Chiang Rai/277/2011 A/Christchurch/4/1985
A/Fujian/411/2002 A/Guangdong-Luohu/1256/2009 A/Hong Kong/1/1968
A/Hong Kong/CUHK31987/2011 A/Indiana/07/2012 A/Memphis/1/68
A/Moscow/10/1999 A/New York/55/2004 A/Perth/16/2009
A/reassortant/IVR-155 A/Sydney/5/1997 A/Texas/50/2012
A/Victoria/208/2009 A/Victoria/210/2009 A/Victoria/3/1975
A/Victoria/361/2011 A/Wisconsin/15/2009 A/Wisconsin/67/X-161/2005
A/Wyoming/03/2003 A/X-31  
H3N8 A/equine/Gansu/7/2008 A/canine/New York/145353/2008  
H4N2 A/duck/Hunan/8-19/2009    
H4N4 A/mallard duck/Alberta/299/1977    
H4N6 A/mallard/Ohio/657/2002 A/Swine/Ontario/01911-1/99  
H4N8 A/chicken/Alabama/1/1975    
H5N1 A/Anhui/1/2005 A/bar-headed goose/Qinghai/14/2008 A/Cambodia/R0405050/2007
A/Cambodia/S1211394/2008 A/chicken/Egypt/2253-1/2006 A/chicken/India/NIV33487/2006
A/Common magpie/Hong Kong/2256/2006 A/Duck/Hong Kong/p46/97 A/duck/Hunan/795/2002
A/duck/Laos/3295/2006 A/Egypt/2321-NAMRU3/2007 A/Egypt/N05056/2009
A/goose/Guiyang/337/2006 A/Hong kong/213/03 A/Hong Kong/483/97
A/Hubei/2011 A/Indonesia/5/2005 A/Japanese white-eye/Hong Kong/1038/2006
A/turkey/Turkey/1/2005 A/Vietnam/UT31413II/2008 A/whooper swan/Mongolia/244/2005
A/Xinjiang/1/2006 A/Vietnam/1194/2004 A/Vietnam/1203/2004
A/Egypt/3300-NAMRU3/2008 A/Thailand/1(KAN-1) /2004 A/barnswallow/Hong Kong/D10-1161/2010
A/chicken/Yamaguchi/7/2004 A/bar-headed goose/Qinghai/1A/2005 A/chicken/VietNam/NCVD-016/2008
A/common magpie/Hong Kong/5052/2007 A/goose/Guangdong/1/96 A/chicken/Jilin/9/2004
A/Hubei/1/2010 A/hubei/2011-CDC  
H5N2 A/American green-winged teal/California/HKWF609/07 A/ostrich/South Africa/AI1091/2006  
H5N3 A/duck/Hokkaido/167/2007    
H5N8 A/breeder duck/Korea/Gochang1/2014 A/broiler duck/Korea/Buan2/2014 A/duck/Jiangsu/k1203/2010
A/duck/NY/191255-59/2002 A/duck/Zhejiang/6D18/2013 A/duck/Zhejiang/W24/2013
A/turkey/Ireland/1378/1983    
H5N9 A/chicken/Italy/22A/1998    
H6N1 A/northern shoveler/California/HKWF115/2007 A/quail/Hong Kong/1721-30/99  
H6N2 A/duck/Shantou/83/2000 A/chicken/Guangdong/C273/2011  
H6N4 A/chicken/HongKong/17/77    
H6N5 A/shearwater/Australia/1/1973    
H6N6 A/duck/Eastern China/11/2009    
H6N8 A/mallard/Ohio/217/1998    
H7N1 A/turkey/Italy/4602/99    
H7N2 A/ruddy turnstone/New Jersey/563/2006    
H7N3 A/chicken/SK/HR-00011/2007 A/turkey/Italy/214845/2002  
H7N7 A/chicken/Netherlands/1/03 A/Netherlands/219/2003 A/equine/Kentucky/1a/1975
H7N8 A/mallard/Netherlands/33/2006    
H7N9 A/Anhui/1/2013 A/Hangzhou/1/2013 A/Pigeon/Shanghai/S1069/2013
A/Shanghai/1/2013 A/Huzhou/10/2013 A/Hangzhou/3/2013
A/Zhejiang/1/2013 A/Zhejiang/DTID-ZJU10/2013 A/Shanghai/4664T/2013
A/Shanghai/Patient3/2013 A/chicken/Zhejiang/DTID-ZJU01/2013 A/Anhui/PA-1/2013
H8N4 A/pintail duck/Alberta/114/1979    
H9N2 A/chicken/Hong Kong/G9/1997 A/Guinea fowl/Hong Kong/WF10/99 A/Hong Kong/1073/99
A/Hong Kong/35820/2009 A/duck/Hong Kong/448/78 A/Hong Kong/3239/2008
A/brambling/Beijing/16/2012 A/Hong Kong/2108/2003  
H9N5 A/shorebird/DE/261/2003     
H9N8 A/chicken/Korea/164/04    
H10N3 A/duck/Hong Kong/786/1979 A/duck/Hunan/S11205/2012 A/mallard/Minnesota/Sg-00194/2007
H10N4 A/mink/Sweden/3900/1984    
H10N7 A/blue-winged teal/Louisiana/Sg-00073/2007    
H10N8 A/Jiangxi-Donghu/346/2013 A/duck/Guangdong/E1/2012  
H10N9 A/duck/HongKong/562/1979    
H11N2 A/duck/Yangzhou/906/2002 A/thick-billed murre/Newfoundland/031/2007  
H11N6 A/duck/England/1/1956    
H11N9 A/mallard/Alberta/294/1977    
H12N1 A/mallard duck/Alberta/342/1983    
H12N3 A/bar headed goose/Mongolia/143/2005    
H12N5 A/green-winged teal/ALB/199/1991    
H13N6 A/black-headed gull/Sweden/1/1999    
H13N8 A/black-headed gull/Netherlands/1/00    
H14N5 A/Mallard/Astrakhan(Gurjev)/263/1982    
H15N2 A/Australian shelduck/Western Australia/1756/1983    
H15N8 A/duck/AUS/341/1983    
H16N3 A/black-headed gull/Sweden/5/99    
H17N10 A/little yellow-shouldered bat/Guatemala/164/2009    
H18N11 A/flat-faced bat/Peru/033/2010    
Influenza B B/Brisbane/3/2007 B/Brisbane/60/2008 B/Florida/07/2004
B/Florida/4/2006 B/Hong Kong/05/1972 B/Malaysia/2506/2004
B/Massachusetts/03/2010 B/Ohio/01/2005 B/PHUKET/3073/2013
B/Utah/02/2012 B/Victoria/02/1987 B/Victoria/504/2000
B/Wisconsin/01/2012 B/Yamagata/16/1988  

Influenza Background Information

Influenza (flu) is a respiratory infection in mammals and birds. It is caused by an RNA virus in the family Orthomyxoviridae. The virus is divided into three main types (Influenza A, Influenza B, and Influenza C), which are distinguished by differences in two major internal proteins (hemagglutinin (HA) and neuraminidase (NA)). Influenza virus type A is found in a wide variety of bird and mammal species and can undergo major shifts in immunological properties. Influenza virus type B is largely confined to humans and is an important cause of morbidity. Little is known about Influenza virus type C, which is not an important source of morbidity.

Influenza A is further divided into subtypes based on differences in the membrane proteins hemagglutinin (HA) and neuraminidase (NA), which are the most important targets for the immune system. The notation HhNn is used to refer to the subtype comprising the hth discovered Hemagglutinin (HA) protein and the nth discovered neuraminidase (NA) protein. The influenza viral Hemagglutinin (HA) protein is a homo trimer with a receptor binding pocket on the globular head of each monomer, and the influenza viral neuraminidase (NA) protein is a tetramer with an enzyme active site on the head of each monomer. Subtypes are further divided into strains; each genetically distinct virus isolate is usually considered to be a separate strain.

Influenza viruses that are known to infect human include the following sub-types. H1N1 virus that caused "Spanish Flu" (A/BrevigMission/1/1918(H1N1)) and seasonal flu (A/Brisbane/59/2007(H1N1), A/New Caledonia/20/1999(H1N1), and A/Solomon Islands/3/2006 (H1N1)) and a reassorted virus (A/California/04/2009(H1N1)) that caused the 2009 swine flu outbreak; H2N2 virus that caused the "Asian Flu"; H3N2 virus that caused the "Hong Kong Flu"; H5N1 "The Bird Flu" virus (A/Anhui/1/2005 (H5N1), A/Vietnam/1203/2004, A/Vietnam/1194/2004 (H5N1), A/bar-headed goose/Qinghai/14/2008 (H5N1), A/turkey/1/2005 (H5N1), A/Indonesia/5/2005 (H5N1)) that was the world's major influenza pandemic threat until the Swine Flu Pandemic of 2009; H7N7 virus that has unusual zoonotic potential; H1N2 is currently endemic in humans and pigs; and H9N2, H7N2, H7N3, H10N7 viruses.

Influenza research involves investigating molecular virology, pathogenesis, host immune responses, genomics, and epidemiology regarding influenza. The main goal of influenza research is to develop influenza countermeasures such as vaccines, therapies and diagnostic tools. Influenza virus vaccination is an effective approach to control influenza virus infection and pandemic spread of the virus. Each seasonal influenza vaccine contains hemagglutinin (HA) and neuraminidase antigen from three influenza subtype viruses-one subtype Influenza A H3N2 virus, one regular seasonal Influenza A H1N1 virus (not the 2009 H1N1 virus), and one Influenza B virus. Because of the influenza virus continues to mutate (antigen minor drifting or antigen major shifting) over time, the viruses in the vaccine change each year based on international surveillance and scientists' estimations about which types and strains of viruses will circulate in a given year. About 2 weeks after vaccination of the influenza viral antigen, antibodies that provide protection against influenza virus infection develop in the body.

Protection mechanism of influenza vaccine is well established to be neutralizing antibody (polyclonal human antibody) raised against in