Influenza - Seasonal
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Influenza virus
photo of influenza

Influenza is a highly contagious viral infection. There are three main antigen types of influenza: types A, B, and C. Influenza type A causes moderate to severe illness and affects all age groups. Type A can infect both humans and animals. Influenza type B generally causes milder disease than type A and primarily affects children. Type B infects only humans. Influenza type C is rarely reported as a cause of human illness. Influenza activity peaks from December to March in the Northern Hemisphere.

Influenza is transmitted from person to person mainly when an infected person coughs or sneezes. Transmission can also occur from direct or indirect contact with respiratory secretions, such as when touching surfaces contaminated with influenza virus and then touching the eyes, nose, or mouth. Transmission can occur from the day before symptoms begin until about 5 days after symptoms begin in adults, or up to 10 days or more after symptoms begin in children.

About 50% of infected persons will develop "classic" influenza disease. This is characterized by the abrupt onset of fever, muscle pain, sore throat, nonproductive cough, runny nose, and headache. These symptoms generally last from 2 to 3 days. However, some people may experience a loss of strength or energy for several weeks. In addition, some people may develop complications, such as pneumonia.      

About the Vaccine

There are two main types of influenza vaccine. The first type is an inactivated vaccine given intramuscularly. There are multiple brands of inactivated influenza vaccine. There is also an intradermal inactivated influenza vaccine. The second type is a live attenuated vaccine given intranasally. Each year new formulations of influenza vaccines are made based on the predicted strains expected to cause illness during that season.

Influenza Vaccine Licensed for Use in the U.S.

Product: Afluria® (Inactivated Influenza Vaccine)
Manufacturer: CSL Biotherapies
Year licensed: 2007
Product Insert

Product: Fluarix® (Inactivated Influenza Vaccine)
Manufacturer: GlaxoSmithKline
Year licensed: 2005
Product Insert

Product: Fluarix Quadrivalent ® (Inactivated Influenza Vaccine)
Manufacturer: GlaxoSmithKline
Year licensed: 2012
Product Insert

Product: Flublok® (Inactivated Influenza Vaccine)
Manufacturer: Protein Sciences Corporation
Year licensed: 2013
Product Insert

Product: Flucelvax® (Inactivated Influenza Vaccine)
Manufacturer: Novartis Vaccines
Year licensed: 2012
Product Insert

Product: FluLaval® (Inactivated Influenza Vaccine)
Manufacturer: GlaxoSmithKline
Year licensed: 2006
Product Insert

Product: FluLaval Quadrivalent® (Inactivated Influenza Vaccine)
Manufacturer: GlaxoSmithKline
Year licensed: 2013
Product Insert

Product Name: FluMist Quadrivalent® (Live Attenuated Influenza Vaccine)
Manufacturer: MedImmune
Year licensed: 2003
Product Insert

Product Name: Fluvirin® (Inactivated Influenza Vaccine)
Manufacturer: Novartis Vaccine
Year licensed: 1988
Product Insert

Product Name: Fluzone® (Inactivated Influenza Vaccine)
Manufacturer: Sanofi Pasteur
Year licensed: 1980
Product Insert

Product Name: Fluzone High-Dose® (Inactivated Influenza Vaccine)
Manufacturer: Sanofi Pasteur
Year licensed: 2009
Product Insert

Product Name: Fluzone Intradermal® (Inactivated Influenza Vaccine)
Manufacturer: Sanofi Pasteur
Year licensed: 2011
Product Insert

Product Name: : Fluzone Quadrivalent® (Inactivated Influenza Vaccine)
Manufacturer: Sanofi Pasteur
Year licensed: 2013
Product Insert

Indications Contraindications and precautions
  • All people 6 months and older.
  • People who have had a severe allergic reaction to a previous dose of influenza vaccine or an influenza vaccine component.*
  • People who are moderately or severely ill should wait until recovery before receiving any vaccine. Minor illnesses, such as a cold, are not a contraindication. Note: If the person has nasal congestion, do not administer influenza vaccine by the intranasal route.
  • People who have a history of Guillain-Barré syndrome (GBS) within 6 weeks of a previous dose of influenza vaccine.
  • LAIV (live attenuated influenza vaccine) may only be given to healthy, nonpregnant persons 2 through 49 years of age.
  • Inactivated influenza vaccine may be given to persons 6 months of age and older. Note: Some brands are not approved for use in younger children.

* Most Influenza vaccine contain egg protein and may contain thimerosal (Thimerosal content varies and preservative-free formulations are available. The tip cap and the rubber plunger of the needleless prefilled syringes may contain dry natural latex rubber (see package insert). Persons with egg allergy who report only hives after egg exposure should receive inactivated influenza vaccine. The vaccine should be given by a healthcare provider who is familiar with signs and symptoms of egg allergy and the vaccine recipient should be monitored for at least 30 minutes for signs and symptoms of allergic reaction. Persons with severe allergy to eggs should be referred to a provider with expertise in the management of allergic conditions for further evaluation. NOTE: FluBlok does not use eggs in its manufacturing process and can be safely given to those with egg allergies.

Vaccine Ages Dose/Route Routine Administration Schedule
Afluria® 5 years of age and older

ACIP does not recommend for children <9 years of age due to risk for febrile seizures.
Dose: 0.5 mL
0.5 mL (3 years of age and older)
Route: Intramuscular (IM)
Single dose annually. Note: Children aged 6 months through 8 years need only 1 dose of vaccine for 2014–15 if they have received any of the following: 1) at least 1 dose of 2013–14 seasonal influenza vaccine; or 2) 2 or more doses of seasonal influenza vaccine since July 1, 2010; or 3) 2 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of monovalent 2009(H1N1) vaccine; or 4) 1 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of seasonal influenza vaccine since July 1, 2010. Children in this age group for whom one of these conditions is not met require 2 doses for 2014–15 administered at least 4 weeks apart.
Fluarix® 3 years of age and older Dose: 0.5 mL
Route: Intramuscular (IM)
Single dose annually. Note: Children aged 6 months through 8 years need only 1 dose of vaccine for 2014–15 if they have received any of the following: 1) at least 1 dose of 2013–14 seasonal influenza vaccine; or 2) 2 or more doses of seasonal influenza vaccine since July 1, 2010; or 3) 2 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of monovalent 2009(H1N1) vaccine; or 4) 1 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of seasonal influenza vaccine since July 1, 2010. Children in this age group for whom one of these conditions is not met require 2 doses for 2014–15 administered at least 4 weeks apart.
Fluarix Quadrivalent® 3 years of age and older Dose: 0.5 mL
Route: Intramuscular (IM)
Single dose annually. Note: Children aged 6 months through 8 years need only 1 dose of vaccine for 2014–15 if they have received any of the following: 1) at least 1 dose of 2013–14 seasonal influenza vaccine; or 2) 2 or more doses of seasonal influenza vaccine since July 1, 2010; or 3) 2 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of monovalent 2009(H1N1) vaccine; or 4) 1 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of seasonal influenza vaccine since July 1, 2010. Children in this age group for whom one of these conditions is not met require 2 doses for 2014–15 administered at least 4 weeks apart.
Flublok® 18 through 49 years of age Dose: 0.5 mL
Route: Intramuscular (IM)
Single dose annually.
Flucelvax® 18 years of age and older Dose: 0.5 mL
Route: Intramuscular (IM)
Single dose annually.
FluLaval® 3 years of age and older Dose: 0.5 mL
Route: Intramuscular (IM)
Single dose annually. Note: Children aged 6 months through 8 years need only 1 dose of vaccine for 2014–15 if they have received any of the following: 1) at least 1 dose of 2013–14 seasonal influenza vaccine; or 2) 2 or more doses of seasonal influenza vaccine since July 1, 2010; or 3) 2 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of monovalent 2009(H1N1) vaccine; or 4) 1 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of seasonal influenza vaccine since July 1, 2010. Children in this age group for whom one of these conditions is not met require 2 doses for 2014–15 administered at least 4 weeks apart.
FluLaval Quadrivalent® 3 years of age and older Dose: 0.5 mL
Route: Intramuscular (IM)
Single dose annually. Note: Children aged 6 months through 8 years need only 1 dose of vaccine for 2014–15 if they have received any of the following: 1) at least 1 dose of 2013–14 seasonal influenza vaccine; or 2) 2 or more doses of seasonal influenza vaccine since July 1, 2010; or 3) 2 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of monovalent 2009(H1N1) vaccine; or 4) 1 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of seasonal influenza vaccine since July 1, 2010. Children in this age group for whom one of these conditions is not met require 2 doses for 2014–15 administered at least 4 weeks apart.
FluMist® Healthy, non-pregnant persons 2 through 49 years of age Dose: 0.2 mL (half into each nostril)
Route: Intranasally
Single dose annually. Note: Children aged 6 months through 8 years need only 1 dose of vaccine for 2014–15 if they have received any of the following: 1) at least 1 dose of 2013–14 seasonal influenza vaccine; or 2) 2 or more doses of seasonal influenza vaccine since July 1, 2010; or 3) 2 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of monovalent 2009(H1N1) vaccine; or 4) 1 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of seasonal influenza vaccine since July 1, 2010. Children in this age group for whom one of these conditions is not met require 2 doses for 2014–15 administered at least 4 weeks apart.
Fluvirin® 4 years of age and older Dose: 0.5 mL
Route: Intramuscular (IM)
Single dose annually. Note: Children aged 6 months through 8 years need only 1 dose of vaccine for 2014–15 if they have received any of the following: 1) at least 1 dose of 2013–14 seasonal influenza vaccine; or 2) 2 or more doses of seasonal influenza vaccine since July 1, 2010; or 3) 2 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of monovalent 2009(H1N1) vaccine; or 4) 1 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of seasonal influenza vaccine since July 1, 2010. Children in this age group for whom one of these conditions is not met require 2 doses for 2014–15 administered at least 4 weeks apart.
Fluzone® 6 months of age and older Dose: 0.25 mL (6 -35 months of age)
0.5 mL (3 years of age and older)
Route: Intramuscular (IM)
Single dose annually. Note: Children aged 6 months through 8 years need only 1 dose of vaccine for 2014–15 if they have received any of the following: 1) at least 1 dose of 2013–14 seasonal influenza vaccine; or 2) 2 or more doses of seasonal influenza vaccine since July 1, 2010; or 3) 2 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of monovalent 2009(H1N1) vaccine; or 4) 1 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of seasonal influenza vaccine since July 1, 2010. Children in this age group for whom one of these conditions is not met require 2 doses for 2014–15 administered at least 4 weeks apart.
Fluzone High-Dose® 65 years of age and older Dose: 0.5 mL
Route: Intramuscular (IM)
Single dose annually. Note: Only licensed for use in persons 65 years of age and older. At this time no preference for use of Fluzone High-Dose vaccine over other inactivated influenza vaccines.
Fluzone Intradermal® 18 through 64 years of age Dose: 0.1 mL
Route: Intradermal
Single dose annually.
Fluzone Quadrivalent® 6 months of age and older Dose: 0.25 mL (6 -35 months of age)
0.5 mL (3 years of age and older)
Route: Intramuscular (IM)
Single dose annually. Note: Children aged 6 months through 8 years need only 1 dose of vaccine for 2014–15 if they have received any of the following: 1) at least 1 dose of 2013–14 seasonal influenza vaccine; or 2) 2 or more doses of seasonal influenza vaccine since July 1, 2010; or 3) 2 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of monovalent 2009(H1N1) vaccine; or 4) 1 or more doses of seasonal influenza vaccine before July 1, 2010, and 1 or more doses of seasonal influenza vaccine since July 1, 2010. Children in this age group for whom one of these conditions is not met require 2 doses for 2014–15 administered at least 4 weeks apart.
Inactivated Influenza Vaccine Side Effects
  • Soreness, redness, or swelling where the shot was given (15-20%).
  • Fever and malaise (<1%).
  • Severe allergic reaction (very rare).
Live Attenuated Influenza Vaccine Side Effects
Some children and adolescents 2 through 17 years of age have reported mild reactions including:
  • Runny nose, nasal congestion, or cough.
  • Headache and muscle aches.
  • Fever.
  • Wheezing.
  • Abdominal pain or occasional vomiting or diarrhea.
  • Severe allergic reaction (very rare).

Some adults 18 through 49 years of age have reported:
  • Runny nose or nasal congestion.
  • Headache
  • Cough, chills, tiredness/weakness.
  • Sore throat.
  • Severe allergic reaction (very rare).
Product Name Supplied Storage and Handling
Afluria®
CSL Biotherapies
0.5 mL single dose prefilled syringes (10 per package), and 5 mL multi-dose vial (1 per package). Store refrigerated between 2° to 8°C (35° to 46°F). Protect from light at all times. Do not freeze. Discard if vaccine has been frozen.

Afluria® is a clear, colorless to slightly opalescent suspension with some sediment that resuspends upon shaking. Shake vial/syringe well before administering.
Agriflu®
Novartis Vaccines
0.5 mL single dose prefilled syringes (10 per package). Store refrigerated between 2° to 8°C (35° to 46°F). Protect from light at all times. Do not freeze. Discard if vaccine has been frozen.

Agriflu® is a clear aqueous suspension. Allow the vaccine to reach room temperature and shake before use.
FluLaval®
GlaxoSmithKline
5 mL multi-dose vial (1 per package). Store refrigerated between 2° to 8°C (35° to 46°F). Protect from light at all times. Do not freeze. Discard if vaccine has been frozen. Once entered, the multi-dose vial should be discarded after 28 days.

FluLaval® is a colorless to slightly opalescent suspension. Shake well before administering.
FluLaval Quadrivalent®
GlaxoSmithKline
5 mL multi-dose vial (1 per package). Store refrigerated between 2°C to 8°C (35°C to 46°CF). Protect from light at all times. Do not freeze. Discard if vaccine has been frozen. Once entered, the multi-dose vial should be discarded after 28 days.

FluLaval® is a colorless to slightly opalescent suspension. Shake well before administering.
Fluarix®
GlaxoSmithKline
0.5 mL single dose prefilled syringes. (10 per package) Store refrigerated between 2° to 8°C (35° to 46°F). Protect from light at all times. Do not freeze. Discard if vaccine has been frozen.

Fluarix® is a colorless to slightly opalescent suspension. Shake well before administering.
Fluarix Quadrivalent®
GlaxoSmithKline
0.5 mL single dose prefilled syringes. (10 per package) Store refrigerated between 2° to 8°C (35° to 46°F). Protect from light at all times. Do not freeze. Discard if vaccine has been frozen.

Fluarix Quadrivalent® is a colorless to slightly opalescent suspension. Shake well before administering.
Flublok®
Protein Sciences Corporation
0.5 mL single dose vial (10 per package). Store refrigerated between 2° to 8°C (35° to 46°F). Protect from light at all times. Do not freeze. Discard if vaccine has been frozen.

Flublok® is a clear, colorless solution. Shake vial gently before withdrawing dose.
Flucelvax®
Novartis Vaccines
0.5 mL single dose prefilled syringes (10 per package). Store refrigerated between 2° to 8°C (35° to 46°F). Protect from light at all times. Do not freeze. Discard if vaccine has been frozen.

Flucelvax® is a slightly opalescent suspension. Shake well before administering.
Fluvirin®
Novartis Vaccines
0.5 mL single dose prefilled syringes (10 per package) and 5 mL multi-dose vial (1 per package). Store refrigerated between 2° to 8°C (35° to 46°F). Protect from light at all times. Do not freeze. Discard if vaccine has been frozen.

Fluvirin® is a slightly opalescent suspension. Shake well before administering.
Fluzone®
Sanofi Pasteur
0.25 mL single dose prefilled syringes (10 per package), 0.5 mL single dose prefilled syringes (10 per package), 0.5 mL single dose vial (10 per package), and 5 mL multi-dose vial (1 per package). Store refrigerated between 2° to 8°C (35° to 46°F). Protect from light at all times. Do not freeze. Discard if vaccine has been frozen.

Fluzone® is a clear to a slightly opalescent suspension. Shake the syringe and single-dose vials well before administering the vaccine and shake the multi-dose vial each time before withdrawing a dose of vaccine.
Fluzone High-Dose®
Sanofi Pasteur
0.5 mL single dose prefilled syringes (10 per package). Store refrigerated between 2° to 8°C (35° to 46°F). Protect from light at all times. Do not freeze. Discard if vaccine has been frozen.

Fluzone High-Dose® is a clear to a slightly opalescent suspension. Shake the syringe well before administering the vaccine.
Fluzone Intradermal®
Sanofi Pasteur
0.1 mL single dose prefilled syringes (10 per package. Store refrigerated between 2° to 8°C (35° to 46°F). Protect from light at all times. Do not freeze. Discard if vaccine has been frozen.

Fluzone Intradermal® is a clear to a slightly opalescent suspension. Gently shake the syringe before administering the vaccine. See product insert for specific instructions on administration.
Fluzone Quadrivalent®
Sanofi Pasteur
0.25 mL single dose prefilled syringes (10 per package), 0.5 mL single dose prefilled syringes (10 per package), and 0.5 mL single dose vial (10 per package). Store refrigerated between 2° to 8°C (35° to 46°F). Protect from light at all times. Do not freeze. Discard if vaccine has been frozen.

Fluzone Quadrivalent® is a clear to a slightly opalescent suspension. Shake the syringe or vial well before administering the vaccine.
FluMist®
MedImmune
0.2 mL single-use sprayers (10 per package). Store refrigerated between 2° to 8°C (35° to 46°F). Do not freeze. Discard if vaccine has been frozen.

FluMist® is a colorless to pale yellow liquid and is clear to slightly cloudy. Administer half of the vaccine into one nostril. Then remove dose divider clip to administer the second half of the vaccine into the opposite nostril.     
MILVAX-VHCN
COMDT COGARD 25 Aug 14
2014-2015 ANNUAL INFLUENZA (FLU) IMMUNIZATION PROGRAM
Author: Potter
Geographic Spread of Influenza as Assessed by State and Territorial Epidemiologists
2013-2014 Influenza Season Week 20 ending May 17, 2014.
Each week the Armed Forces Health Surveillance Center publishes a summary of influenza activity in the COCOMS. The summary tracks influenza like illness, flu activity through the DoD laboratory surveillance network and influenza vaccination coverage. Reports are by COCOM and service members or beneficiary populations.
On November 20th the FDA announced approval of Flucelvax, the first seasonal influenza vaccine licensed in the United States produced using cultured animal cells, instead of fertilized chicken eggs. Flucelvax is approved to prevent seasonal influenza in people ages 18 years and older. The manufacturing process is similar to the egg-based production method, but a significant difference is that the virus strains included in the vaccine are grown in animal cells of mammalian origin instead of in eggs. Cell culture technology has already been in use for several decades to produce other U.S. licensed vaccines.
This is a 5 module online course, plus quiz, that will provide Military Healthcare Personnel with important and comprehensive information concerning the influenza vaccine.
COMDT COGARD PDF 25 Aug 14
2014-2015 ANNUAL INFLUENZA (FLU) IMMUNIZATION PROGRAM
GENADMIN PDF 21 Jun 13
III MEF FORCE HEALTH PROTECTION (FHP) REQUIREMENTS 2014
02 Jan 14

Sample Q&A: The Disease

How soon will I get sick after exposure to the influenza virus?
Most healthy adults may be able to infect others beginning 1 day before symptoms develop and up to 5 to 7 days after becoming sick. Children may pass the virus for longer than 7 days. Symptoms start 1 to 4 days after the virus enters the body. That means that you may be able to pass on the flu to someone else before you know you are sick, as well as while you are sick. Some persons can be infected with the flu virus but have no symptoms. During this time, those persons may still spread the virus to others.
Recommendations of the Advisory Committee on Immunization Practices (ACIP)
Recommendations of the Advisory Committee on Immunization Practices - United States, 2013 & 2014
Summary Recommendations of the Advisory Committee on Immunization Practices, United States, 2013-14. The full recommendations will be published in Morbidity and Mortality Weekly Report (MMWR).
Recommendations of the Advisory Committee on Immunization Practices (ACIP)
Information on DoD Online 2014-15 Seasonal Influenza Vaccination Training
2 CDC videos emphasizing importance of flu vaccination for children between 6 months - 18 years
Recommendations of the Defense Health Board (DHB)
Recommendations of the Defense Health Board (DHB)
Recommendations of the Armed Forces Epidemiological Board (AFEB)
Package Insert - Vaccine
Package Insert - Vaccine
Package Insert - Vaccine
Package Insert - Vaccine (not centrally contracted)
Package Insert - Vaccine (not centrally contracted)
MedImmune 07 Jul 14
FluMist Quadrivalent
Sanofi-Pasteur 07 Jul 14
Fluzone Quadrivalent
Novartis 07 Jul 14
Flucelvax Trivalent
Novartis 07 Jul 14
Fluvirin Trivalent
GlaxoSmithKline 07 Jul 14
Flulaval Quadrivalent
GlaxoSmithKline 07 Jul 14
Flulaval Trivalent
Afluria
MMQC-14-1736 19 Aug 14
Influenza Virus Vaccine (AFLURIA) / CSL Behring / bioCSL
MMQC-14-1126 18 Feb 14
2013 - 2014 Influenza Virus Vaccine / Disposition Instructions
MMI-14-4001 31 Jan 14
2014 - 2015 INFLUENZA VIRUS VACCINE - CALL FOR REQUIREMENTS / SUSPENSE: 28 FEBRUARY 2014
MMQC-13-2030 06 Nov 13
Flumist Replacement Program (2013/2014) Influenza Vaccine Season / SUSPENSE: 31 JANUARY 2014
MMQC-12-1004 09 Jan 12
FDA UPDATED COMMUNICATION ON USE OF JET INJECTORS WITH INACTIVATED INFLUENZA VACCINES
Video Instructions, produced by MILVAX, length (3:14)
Centers for Disease Control and Prevention; National Center for Immunization and Respiratory Diseases (NCIRD)
Video: I Never Get the FluI Never Get the Flu (1:00) 10 Jan 13
Centers for Disease Control and Prevention; National Center for Immunization and Respiratory Diseases (NCIRD)

The National Institute of Allergy and Infectious Diseases explains the emergence and potential spread of new influenza viruses.


A Public Service Announcement by Army Surgeon General, LTG Patricia D. Horoho, about Immunization Awareness Month & the importance of the annual influenza vaccine.
Have you ever wondered why you need a flu vaccination each year? The National Institute of Allergy and Infectious Diseases explains the ever-changing nature of influenza viruses.
NFID Flu F.A.C.T.S. - Taking some simple steps, like washing your hands to stop the spread of germs and getting an annual flu shot, can help protect you from the flu.
1st Stryker Brigade Combat Team, 25th Infantry Division Brigade Support Medical Company vaccinates soldiers in southern Afghanistan in preparation of the upcoming flu season.
Vaccine Information Statement (Interim), Live, Attenuated Influenza Vaccine
Vaccine Information Statement (Interim), Inactivated Influenza Vaccine
CBS News 26 Jun 14
For kids, flu spray may be better than shots
Author(s): Fuller T, Gilbert M, Martin V, Cappelle J, Hosseini P, Njabo K, Abdel Aziz S, Xiao X, Daszak P, Smith T
Publication: Emerging Infectious Diseases
Subject: Disease
Disease: 
Influenza - Seasonal
Influenza - Pandemic
Author(s): Greenhawt MJ, Li JT
Publication: Annals of Allergy, Asthma & Immunology, vol. 106
Subject: Vaccine-Safety
Disease: 
Influenza - Seasonal
Author(s): Government Accountability Office
Publication: GAO-13-374T
Subject: Vaccine-General
Disease: 
Influenza - Seasonal
Influenza - Pandemic
Author(s): Monto AS, Ohmit SE, Petrie JG, Johnson E, Truscon R, Teich E, Rotthoff J, Boulton M, Victor JC
Publication: NEJM
Subject: Vaccine-Effectiveness
Disease: 
Influenza - Seasonal