View source for Influenza primary prevention

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{{Influenza}}
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==Overview==
[[Vaccination]] and [[chemoprophylaxis]] are the two most important methods for preventing influenza among patients.  Routine annual [[influenza vaccination]] is recommended for all persons aged ≥6 months who do not have contraindications.  Annual influenza [[vaccination]] is the best way to prevent influenza because [[vaccination]] can be given well before influenza virus exposures occur, and can provide safe and effective immunity throughout the influenza season.  [[Chemoprophylaxis]] is not recommended in all patients and should only be administered for certain populations who are at risk of complications.

==Vaccination==
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! style="background: #4479BA; color:#FFF;" |Contraindications for Live Attenuated Influenza Vaccine
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* Persons aged <2 years or >49 years
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* Those with contraindications listed in the package insert:
:* Children aged 2 through 17 years who are receiving aspirin or aspirin-containing products
:* Persons who have experienced severe allergic reactions to the vaccine or any of its components, or to a previous dose of any influenza vaccine
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* Pregnant women
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* Immunosuppressed persons
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* Persons with a history of egg allergy
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* Children aged 2 through 4 years who have asthma or who have had a wheezing episode noted in the medical record within the past 12 months, or for whom parents report that a health care provider stated that they had wheezing or asthma within the last 12 months.
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* Persons who have taken influenza antiviral medications within the previous 48 hours.
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|style="padding: 0px 5px; background: #DCDCDC;"| <Small>Adapted from CDC Prevention and Control of Seasonal Influenza with Vaccines<ref> {{Cite web|url=http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6332a3.htm#fig1| title=Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices (ACIP) — United States, 2014–15 Influenza Season}} </ref></small>
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|[[File:Influenza vaccine.jpg|thumb|180px|Intradermal influenza vaccine <br> Image courtesy of Public Health Image Library (PHIL)]]
|[[File:Intranasal Influenza vaccine.jpg|thumb|180px|Intranasal influenza vaccine <br> Image courtesy of Public Health Image Library (PHIL)]]
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{{further|[[Flu vaccine]]}}

*Vaccination against influenza with a [[flu vaccine]] is strongly recommended for high-risk groups, such as children and the elderly.
*Health care providers should offer vaccination soon after vaccine becomes available (by October, if possible).
*Vaccination should be offered as long as influenza viruses are circulating.
*Children aged 6 months through 8 years who require 2 doses should receive their first dose as soon as possible after vaccine becomes available, and the second dose ≥4 weeks later. 

====2014-15 Influenza Vaccines====
*For 2014–15, U.S.-licensed influenza vaccines will contain the same vaccine virus strains as those in the 2013–14 vaccine. 
*Starting in 2014-2015, CDC recommends use of the nasal spray vaccine (LAIV) for healthy children 2 through 8 years of age, when it is immediately available and if the child has no contraindications or precautions to that vaccine.
*Trivalent influenza vaccines will contain hemagglutinin (HA) derived from an A/California/7/2009 (H1N1)-like virus, an A/Texas/50/2012 (H3N2)-like virus, and a B/Massachusetts/2/2012-like (Yamagata lineage) virus.
*Quadrivalent influenza vaccines will contain these antigens, and also a B/Brisbane/60/2008-like (Victoria lineage) virus.

====Influenza Vaccine Dosing Algorithm For Children Aged 6 Months Through 8 Years====
<Small><small>Algorithm adapted from CDC Prevention and Control of Seasonal Influenza with Vaccines<ref> {{Cite web|url=http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6332a3.htm#fig1| title=Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices (ACIP) — United States, 2014–15 Influenza Season}} </ref></small></small>
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{{familytree  |boxstyle=border-radius: 5px 5px 5px 5px;border: 1px;background: #4479BA; color: #F8F8FF;| B01 | | | | | | B02 | | | B01= '''Yes''' | B02=<div style="width:10em"> '''No or don't know'''</div>}}
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{{familytree  |boxstyle=border-radius: 5px 5px 5px 5px;border: 1px;background: #4479BA; color: #F8F8FF;| C01 | | | | | | C02 | | | C01=<div style="width:10em"> Administer 1 dose</div> | C02=<div style="width:10em"> Did the child receive a total of at least 2 doses of influenza vaccine since July 2010?</div>}}
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{{familytree  |boxstyle=border-radius: 5px 5px 5px 5px;border: 1px;background: #4479BA; color: #F8F8FF;| | | | | | B01 | | | | B02 | B01=<div style="width:10em">'''Yes'''</div>| B02= '''No or don't know'''}}
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{{familytree  |boxstyle=border-radius: 5px 5px 5px 5px;border: 1px;background: #4479BA; color: #F8F8FF;| | | | | | C01 | | | | C02 | C01=<div style="width:10em">Administer 1 dose</div> | C02=<div style="width:10em"> Administer 2 doses</div>}}
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===Duration of Immunity===
*The composition of influenza vaccines is changed in most seasons, with one or more vaccine strains replaced annually to provide protection against viruses that are anticipated to circulate. 
*Protection against viruses that are antigenically similar to those contained in the vaccine extends at least for 6–8 months, particularly in non-elderly populations. 
*In some situations, duration of immunity might be longer, and such effects can be detected if circulating influenza virus strains remain antigenically similar for multiple seasons. 
*Serum HAI influenza antibodies and nasal IgA elicited by vaccination remain detectable in children vaccinated with LAIV for >1 year after vaccination.
*Adults aged ≥65 years typically have diminished immune responses to influenza vaccination compared with healthy younger adults. 
*Limited available data suggest that administration of additional vaccine doses during the same season does not increase the antibody response among elderly vaccines.



==Chemoprophylaxis<small><small><small> Adapted from CDC <ref name="CDC Antivirals"> {{cite web| url=http://www.cdc.gov/flu/professionals/antivirals/summary-clinicians.htm| title=CDC Influenza Antiviral Medications: Summary for Clinicians}}</ref></small></small></small>==
* [[Antiviral medications]] are approximately 70% to 90% effective in preventing influenza and are useful adjuncts to influenza [[vaccination]].
* CDC does not recommend widespread or routine use of [[antiviral medications]] for chemoprophylaxis so as to limit the possibilities that antiviral resistant viruses could emerge. 
*Indiscriminate use of chemoprophylaxis might promote resistance to [[antiviral medications]], or reduce antiviral medication availability for treatment of persons at higher risk for influenza complications or those who are severely ill.
* In general, CDC does not recommend seasonal or pre-exposure antiviral chemoprophylaxis, but [[antiviral medications]] can be considered for chemoprophylaxis in certain situations.
* The following are examples of situations where [[antiviral medications]] can be considered for chemoprophylaxis to prevent influenza:
:* Prevention of influenza in persons at high risk of influenza complications during the first two weeks following [[vaccination]] after exposure to an infectious person.
:* Prevention for people with severe immune deficiencies or others who might not respond to influenza [[vaccination]], such as persons receiving immunosuppressive medications, after exposure to an infectious person.
:* Prevention for people at high risk for complications from influenza who cannot receive influenza vaccine due to a contraindication after exposure to an infectious person.
:* Prevention of influenza among residents of institutions, such as long-term care facilities, during influenza outbreaks in the institution.
* An emphasis on close monitoring and early initiation of antiviral treatment if fever and/or respiratory symptoms develop is an alternative to chemoprophylaxis after a suspected exposure for some persons.
* To be effective as chemoprophylaxis, an antiviral medication must be taken each day for the duration of potential exposure to a person with influenza and continued for 7 days after the last known exposure. For persons taking antiviral chemoprophylaxis after inactivated influenza [[vaccination]], the recommended duration is until immunity after [[vaccination]] develops (antibody development after [[vaccination]] takes about two weeks in adults and can take longer in children depending on age and [[vaccination]] history).
* Antiviral chemoprophylaxis generally is not recommended if more than 48 hours have elapsed since the first exposure to an infectious person.
* Patients receiving antiviral chemoprophylaxis should be encouraged to seek medical evaluation as soon as they develop a febrile respiratory illness that might indicate influenza.

==Dosaga and administration==
                     If vaccine is administered for the first time in a 6 month to 8-year-old child, who has never got the flu vaccine before or vaccine history is unknown, it is given as 2 doses, 4 weeks apart. Two forms of flu vaccines are available- inactivated (injectable) vaccine (IIV) -dosage is 0.25cc administered as intramuscular vaccine for 6 to 35 month kid, for 36 months to 9 years kid dosage is 0.5 cc. The other form is live attenuated inactivated vaccine (LAIV) -given only for more than 2 years kid and within 50 years-dosage 0.2 cc sprayed as 0.1 cc in each nostril. Flu Vaccine is administered once every year for recommended population between October and April.  

==CDC Public Campaigns and Awareness==
The following images are provided by the CDC to physicians to promote vaccination among high risk groups and healthcare workers. 
<gallery>
Image:CDC obgyn-flu-card.png
Image:CDC obgyn-flu-card 2.png
Image:Healthcare Poster CDC.png
</gallery>

==References==
{{Reflist|2}}

[[Category:Disease]]
[[Category:Pulmonology]]
[[Category:Influenza| ]]
[[Category:Infectious disease]]
[[Category:Primary care]]

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