# Presentation: 453789

## Influenza and Influenza Vaccine

**Epidemiology and Prevention of Vaccine-Preventable Diseases**
**National Immunization Program**
**Centers for Disease Control and Prevention**

**Revised January 2007**

## NOTICEContent and order of the slides in this file may differ from those presented on the  broadcast and webcast

## Influenza Virus

**Orthomyxoviridae family**
**3 types: A, B, C**
**Subtypes of type A determined by hemagglutinin and neuraminidase**

## Influenza Virus

## Influenza Antigenic Changes

**Antigenic Drift**
**minor change, same subtype**
**caused by point mutations in gene**
**may result in epidemic**
**Antigenic Shift**
**major change, new subtype**
**caused by exchange of gene segments**
**may result in pandemic**

## Influenza Type A Antigenic Shifts

_**Year**_
**1889**
**1918**
**1957**
**1968**
**1977**

_**Subtype**_
**H3N2**
**H1N1**
**H2N2**
**H3N2**
**H1N1**

**Severity of**
_**Pandemic**_
**  ****Moderate**
**  ****Severe**
**  ****Severe**
**  ****Moderate**
**  ****Mild**

## Avian Influenza (H5N1)*

**271 human infections with 165 (61%)  deaths**
**More than half of the cases in 2006, and almost all of the cases in 2007 have occurred in Indonesia**
**To date, no infections caused by the highly pathogenic form of H5N1 have been reported in the United States**
**Contact with dead or sick birds is the principal source of human infection  **

***as of February 3, 2007. WHO data**

##  Influenza Clinical Features

**Incubation period 1-4 days**
**Abrupt onset of fever, myalgia, sore throat, nonproductive cough, headache**
**Severity of illness from influenza depends on prior immunologic experience with antigenically related variants **

## Influenza Complications

**Pneumonia**
**primary influenza**
**secondary bacterial**
**Reye syndrome**
**Myocarditis**
**Death 0.5-1 per 1,000 cases**

## Impact of Influenza

**36,000 influenza-associated pulmonary and circulatory deaths occurred during each influenza season **
**Persons 65 years of age and older account for more than 90% of deaths **
**More than 200 thousand influenza-related hospitalizations per year **

## Hospitalization Rates for Influenza By Age and Risk Group*

_**Age Group**_
**0-11 mos**
**1-2 yrs**
**3-4 yrs**
**5-14 yrs**
**15-44 yrs**
**45-64 yrs**
_**>**_**65 yrs**

**  ****Rate****
_**(high-risk)**_
**1900**
**800**
**320**
**92**
**56-110**
**392-635**
**399-518**

** ****Rate****
_** **__**(not high-risk)**_
**496-1038**
**186**
**86**
**41**
**23-25**
**13-23**
**125-228**

** ***** Data from several studies 1972 - 1995**
**** Hospitalizations per 100,000 population**

## Influenza Vaccines

**Live attenuated vaccine (LAIV)**
**intranasal**
**trivalent****	**
**Inactivated subunit (TIV)**
**intramuscular**
**trivalent**

## Trivalent (H3N2, H1N1, B)
Efficacy varies
Duration of immunity for inactivated influenza vaccine is considered to be 1 year or less
Duration of immunity for LAIV is uncertain  

**Efficacy varies**
**Duration of immunity for inactivated influenza vaccine is considered to be 1 year or less**
**Duration of immunity for LAIV is uncertain  **

**Influenza Vaccines**

## Inactivated Influenza Vaccine Efficacy

**70%-90% effective among healthy persons <65 years of age**
**30%-40% effective among frail elderly persons**
**50%-60% effective in preventing hospitalization**
**80% effective in preventing death**

## Influenza and Complications Among Nursing Home Residents

**Influenza and Complications Among Nursing Home Residents**

**RR=1.9**

**RR=2.0**

**RR=2.5**

**RR=4.2**

***Inactivated influenza vaccine. Genesee County, MI, 1982-1983**

## Inactivated Influenza Vaccines Available in 2006-2007

| Vaccine | Package | Dose | Age | Thimerosal |
| --- | --- | --- | --- | --- |
| Fluzone
(sanofi pasteur) | Multi-dose vial* | Age-dependent | >6 mos | Yes |
|    | Single dose syringe* | 0.25 mL | 6-35 mos | No |
|    | Single dose syringe* | 0.5 mL | >36 mos | No |
|    | Single dose vial* | 0.5 mL | >36 mos | No |
| Fluvirin
(Novartis) | Multi-dose vial | 0.5 mL | >4 yrs | Yes |
| Fluarix
(GSK) | Single dose syringe | 0.5 mL | >18 yrs | Trace |
| FluLaval
(GSK) | Multi-dose vial | 0.5 mL | >18 yrs | Yes |

***vaccines approved for children younger than 4 years **

## Composition of the 2006-2007 Influenza Vaccine 

**A/New Caledonia/20/99 (H1N1)**
**B/Malaysia/2506/2004**
**A/Wisconsin/67/2005 (H3N2)**
**   **

## Inactivated Influenza Vaccine Schedule

**Age**
_**Group**_
**6-35 mos**
**3-8 yrs**
_**>**_**9 yrs**

_**Dose**_
**0.25 mL**
**0.50 mL**
**0.50 mL**

**No.**
_**Doses**_
**1* or 2**
**1* or 2**
**1**

***Only one dose is needed if the child received influenza vaccine during a previous influenza season**

##    Live Attenuated Influenza Indications

**Healthy* persons 5-49 years of age**
**Do not administer LAIV to children younger than 5 years, or to adults older than 49 years**
**The dose of LAIV is 0.5 mL regardless of age **

***Persons who do not have medical conditions that increase their risk for complications of influenza**

##    Live Attenuated Influenza VaccineSchedule

_**Group**_
**5-8 yrs**
** ****-no previous influenza**
**  ****vaccine**
**-previous influenza**
**  ****vaccine**
**9-49 yrs**

**No.**
_**Doses**_
**2 (separated by 6-10 wks)**
**1**
**1**

**   ****Live Attenuated Influenza Vaccine****Schedule**

## Inactivated Influenza Vaccine Recommendations

**All persons 50 years of age or older**
**Persons **_**>**_**6 months of age with chronic illness**
**Children 6-59 months of age**

## Inactivated Influenza Vaccine Recommendations

**Persons with the following chronic illnesses should be considered for inactivated influenza vaccine:**
**pulmonary (e.g., emphysema, asthma)**
**cardiovascular (e.g., CHF)**
**metabolic (e.g., diabetes)**
**renal dysfunction**
**hemoglobinopathy**
**immunosuppression, including HIV infection**
**any condition that can compromise respiratory function or the handling of respiratory secretions or that can increase the risk of aspiration **

## HIV Infection and Inactivated Influenza Vaccine

**Persons with HIV at increased risk of complications of influenza**
**Transient increase in HIV replication reported**
**No progression of clinical HIV disease **
**TIV will benefit many HIV-infected persons**
**LAIV should not be administered to persons with HIV infection **

## Inactivated Influenza Vaccine Recommendations

**Residents of long-term care facilities**
**Persons 6 months through 18 years of age receiving chronic aspirin therapy**
**Pregnant women **

## Pregnancy and Inactivated Influenza Vaccine

**Risk of hospitalization 4 times higher than nonpregnant women**
**Risk of complications comparable to nonpregnant women with high-risk medical conditions**
**ACIP recommends vaccination for all women who will be pregnant during influenza season**

## Influenza Vaccine Recommendations*

**Providers of essential community services**
**International travelers**
**Students**
**Anyone who wants to reduce the likelihood of becoming ill from influenza**

***these groups may receive TIV; some may be **
** ****eligible for LAIV**

## Influenza Vaccine Recommendations

**Household contacts of high-risk persons**
**Healthcare providers, including home care***
**Employees of long-term care facilities**

***LAIV should not be administered to healthcare workers who have contact with severely immunosuppressed persons who require hospitalization and care in a protective environment**

## Benefits of Influenza Vaccination of Healthcare Personnel (HCP)

**Reduction in nosocomial influenza and influenza-related deaths**
**Reduction in staff illness and illness-related absenteeism**
**Reduction of direct medical costs and indirect costs from work absenteeism**

**Source:***** MMWR***** 2006;55 (RR-2)**

## Influenza Vaccination of Healthcare Personnel

**Only 42 percent of U.S. healthcare personnel  were vaccinated in 2004 **

## Reasons HCP Do Not Receive Influenza Vaccine

**Concern about vaccine adverse events**
**Perception of a low personal risk of **
**influenza virus infection**
**Insufficient time or inconvenience**
**Reliance on homeopathic medications**
**Avoidance of all medications**
**Fear of needles**

**Source:***** MMWR***** 2006;55 (RR-2)**

## Factors Facilitating HCP Influenza Vaccination

**Desire for self-protection**
**Previous receipt of influenza vaccine**
**Desire to protect patients**
**Perceived effectiveness of the vaccine**

**Source:***** MMWR***** 2006;55 (RR-2)**

## Strategies to Improve HCPInfluenza Vaccination Levels

**Education**
**Role models**
**Reduction of financial and time barriers**
**Monitor and report influenza vaccination levels in the facility**
**Signed vaccination declination* (?)**
**Legislation and regulation (?)**

***Examples of vaccination declination forms available in *****Infection Control and Hospital Epidemiology*****, November 2005, and from the Immunization Action Coalition at www.immunize.org**

## Inactivated Influenza Vaccine Recommendations

**Continue to offer influenza vaccine, especially to those at high risk of complications, and to healthcare personnel for as long as influenza viruses are circulating in their communities **

## Live Attenuated Influenza Vaccine

**Approved for use ONLY for healthy nonpregnant persons 5 years through 49 years of age**
**healthcare personnel**
**other persons in close contact with high-risk groups, such as household contacts**
**persons who want to reduce their risk of influenza **

**Source:***** MMWR***** 2006;55 (RR-10)**

## Simultaneous Administration of LAIV and Other Vaccines

**Inactivated vaccines can be administered either simultaneously* or at any time before or after LAIV**
**Other live vaccines can be administered at the same visit* as LAIV**
**Live vaccines not administered on the same day should be delayed at least 4 weeks**

***off-label ACIP recommendation**

## Inactivated Influenza Vaccine Adverse Reactions

**	****Local reactions****	****	****15%-20%**
**	****Fever, malaise****	****	****	****not common**
**	****Allergic reactions****	****	****rare**
**	****Neurologic****	****	****	****	****very rare**
**   ****reactions**

## Live Attenuated Influenza VaccineAdverse Reactions

**Children**
**significantly increased risk of asthma or reactive airways disease in children 12-59 months of age**
**no significant increase in URI symptoms, fever, or other systemic symptoms **
**Adults**
**significantly increased rate of cough, runny nose, nasal congestion, sore throat, and chills reported among vaccine recipients**
**no increase in the occurrence of fever**
**No serious adverse reactions reported **

## Inactivated Influenza VaccineContraindications and Precautions

**Severe allergic reaction to a vaccine component (e.g., egg) or following a prior dose of vaccine**
**Moderate or severe acute illness**

## Live Attenuated Influenza VaccineContraindications and Precautions

**Children <5 years of age***
**Persons **_**>**_**50 years of age***
**Persons with underlying medical conditions*including immunosuppression**
**Children 18 years and younger receiving long-term aspirin therapy***

***These persons should receive inactivated influenza vaccine**

## Live Attenuated Influenza VaccineContraindications and Precautions

**Pregnant women***
**History of Guillian-Barré syndrome**
**Severe (anaphylactic) allergy to egg or other vaccine components**
**Moderate or severe acute illness  **

***These persons should receive inactivated influenza vaccine**

## LAIV Storage and Handling

**Must be stored at **_**<**_**5****°****F (-15****°****C ) **
**May be stored in a frost-free freezer with a separate door**
**Keep the vaccine frozen until immediately before it is used **
**May be stored in a refrigerator and stored at 35°-46°F (2°-8°C) for up to 60 hours before use**
**Thawed vaccine cannot be refrozen**

## Influenza Antiviral Use, 2006-2007*

**Neither amantadine nor rimantadine be used for the treatment or chemoprophylaxis of influenza A infections in the United States during the 2006- 2007 influenza season**
**Oseltamivir (Tamiflu) or zanamivir (Relenza) should be prescribed if an antiviral drug is indicated for the treatment or chemoprophylaxis of influenza **

***see influenza ACIP statement or CDC influenza website for details**

## National Immunization ProgramContact Information

**Telephone****	****	****800.CDC.INFO**** **
**Email****	****	****	****nipinfo@cdc.gov**** **
**Website****	****	****www.cdc.gov/nip**