Seasonal Influenza (Flu)

Recommendations for Using TIV and LAIV During the 2009–10 Influenza Season

Both TIV and LAIV prepared for the 2009--10 season will include A/Brisbane/59/2007 (H1N1)-like, A/Brisbane/10/2007 (H3N2)-like, and B/Brisbane/60/2008-like antigens. The influenza B virus component of the 2009--10 vaccine is from the Victoria lineage. These viruses will be used because they are representative of seasonal influenza viruses that are predicted to be circulating in the United States during the 2009--10 influenza season and have favorable growth properties in eggs. Seasonal influenza vaccines are not expected to provide substantial protection against infection with the recently identified novel influenza A (H1N1), and guidance for the prevention of infection against this virus will be published separately.

TIV and LAIV can be used to reduce the risk for influenza virus infection and its complications. Vaccination providers should administer influenza vaccine to any person who wishes to reduce the likelihood of becoming ill with influenza or transmitting influenza to others should they become infected.

Healthy, nonpregnant persons aged 2--49 years can choose to receive either vaccine. Some TIV formulations are FDA-licensed for use in persons as young as age 6 months (see Recommended Vaccines for Different Age Groups). TIV is licensed for use in persons with high-risk conditions (Table 2). LAIV is FDA-licensed for use only for persons aged 2--49 years. In addition, FDA has indicated that the safety of LAIV has not been established in persons with underlying medical conditions that confer a higher risk for influenza complications. All children aged 6 months--8 years who have not been vaccinated previously at any time with at least 1 dose of either LAIV (if appropriate) or TIV should receive 2 doses of age-appropriate vaccine in the same season, with a single dose during subsequent seasons.

Target Groups for Vaccination

Influenza vaccine should be provided to all persons who want to reduce the risk for becoming ill with influenza or of transmitting it to others. However, emphasis on providing routine vaccination annually to certain groups at higher risk for influenza infection or complications is advised, including all children aged 6 months--18 years, all persons aged 50 years and older, and other adults at risk for medical complications from influenza. In addition, all persons who live with or care for persons at high risk for influenza-related complications, including contacts of children aged <6 months, should receive influenza vaccine annually (Boxes 1 and 2). Approximately 85% of the U.S. population is included in one or more of these target groups; however, <40% of the U.S. population received an influenza vaccination during the 2008--09 influenza season.

Children Aged 6 Months –18 years

Beginning with the 2008--09 influenza season, annual vaccination for all children aged 6 months--18 years was recommended. Children and adolescents at high risk for influenza complications should continue to be a focus of vaccination efforts as providers and programs transition to routinely vaccinating all children.

Healthy children aged 2--18 years can receive either LAIV or TIV. Children aged 6--23 months, and those aged 2--4 years who have evidence of asthma wheezing or who have medical conditions that put them at higher risk for influenza complications should receive TIV (see Considerations When Using LAIV). All children aged 6 months--8 years who have not received vaccination against influenza previously should receive 2 doses of vaccine the first year they are vaccinated.

Persons at Increased Risk for Medical Complications

Vaccination to prevent influenza is particularly important for the following persons, who are at increased risk for severe complications from influenza, or at higher risk for influenza-related outpatient, ED, or hospital visits:

all children aged 6 months--4 years (59 months);
all persons aged 50 years and older;
children and adolescents (aged 6 months--18 years) who are receiving long-term aspirin therapy and who might be at risk for experiencing Reye syndrome after influenza virus infection;
women who will be pregnant during the influenza season;
adults and children who have chronic pulmonary (including asthma) or cardiovascular (except hypertension), renal, hepatic, neurological/neuromuscular, hematologic, or metabolic disorders (including diabetes mellitus);
adults and children who have immunosuppression (including immunosuppression caused by medications or by HIV); and
residents of nursing homes and other long-term--care facilities.

For children, the risk for severe complications from seasonal influenza is highest among those aged <2 years, who have much higher rates of hospitalization for influenza-related complications compared with older children. Medical care and ED visits attributable to influenza are increased among children aged <5 years compared with older children. Chronic neurologic and neuromuscular conditions include any condition (e.g., cognitive dysfunction, spinal cord injuries, seizure disorders, or other neuromuscular disorders) that can compromise respiratory function or the handling of respiratory secretions or that can increase the risk for aspiration.

Persons Who Live With or Care for Persons at High Risk for Influenza-Related Complications

To prevent transmission to persons identified above, vaccination with TIV or LAIV (unless contraindicated) also is recommended for the following persons. When vaccine supply is limited, vaccination efforts should focus on delivering vaccination to these persons:

Healthcare professionals;
household contacts (including children) and caregivers of children aged 59 months and younger (i.e., aged <5 years) and adults aged 50 years and older; and
household contacts (including children) and caregivers of persons with medical conditions that put them at higher risk for severe complications from influenza.

TABLE 2. Approved influenza vaccines for different age groups --- United States, 2009–10 season
Vaccine	Trade name	Manufacturer	Presentation	Mercury content (mcg Hg/0.5 mL dose)	Age group	No. of doses	Route
TIV*	Fluzone	Sanofi Pasteur	0.25mL prefilled syringe	0	6–35 mos	1 or 2†	Intramuscular §
			0.5 mL prefilled syringe	0	36 mos and older	1 or 2	Intramuscular
			0.5 mL vial	0	36 mos and older	1 or 2	Intramuscular
			>5.0 mL multidose vial	25	6 mos and older	1 or 2	Intramuscular
TIV	Fluvirin	Novartis Vaccine	5.0 mL multidose vial	25	4 yrs and older	1 or 2	Intramuscular
TIV	Fluvirin	Novartis Vaccine	0.5 mL prefilled syringe	<1.0	4 yrs and older	1 or 2	Intramuscular
TIV	Fluarix	GlaxoSmithKline	0.5 mL prefilled syringe	0	18 yrs and older	1	Intramuscular
TIV	FluLaval	GlaxoSmithKline	5.0 mL multidose vial	25	18 yrs and older	1	Intramuscular
TIV	Afluria	CSL Biotherapies	0.5 mL prefilled syringe	0	18 yrs and older	1	Intramuscular
TIV	Afluria	CSL Biotherapies	5.0 mL multidose vial	25	18 yrs and older	1	Intramuscular
LAIV¶	FluMist**	MedImmune	0.2 – mL sprayer	0	2–49 yrs	1 or 2 ††	Intranasal
* Trivalent inactivated vaccine. A 0.5-mL dose contains 15 mcg each of A/Brisbane/59/2007 (H1N1)-like, A/Brisbane/10/2007 (H3N2)-like, and B/Brisbane/60/2008-like antigens. † Two doses administered at least 1 month apart are recommended for children aged 6 months--8 years who are receiving TIV for the first time and those who only received 1 dose in their first year of vaccination should receive 2 doses in the following year. §For adults and older children, the recommended site of vaccination is the deltoid muscle. The preferred site for infants and young children is the anterolateral aspect of the thigh. ¶Live attenuated influenza vaccine. A 0.2-mL dose contains 106.5--7.5 fluorescent focal units of live attenuated influenza virus reassortants of each of the three strains for the 2008--09 influenza season: A/Brisbane/59/2007(H1N1), A/Brisbane/10/2007(H3N2), and B/Brisbane/60/2008. ** FluMist is shipped refrigerated and stored in the refrigerator at 2°C--8°C (36° F to 46°F) after arrival in the immunization clinic. The dose is 0.2 mL divided equally between each nostril. FluMist should not be administered to persons with asthma. Health-care providers should consult the medical record, when available, to identify children aged 2--4 years with asthma or recurrent wheezing that might indicate asthma. In addition, to identify children who might be at greater risk for asthma and possibly at increased risk for wheezing after receiving FluMist, parents or caregivers of children aged 2--4 years should be asked: "In the past 12 months, has a health-care provider ever told you that your child had wheezing or asthma?" Children whose parents or caregivers answer "yes" to this question and children who have asthma or who had a wheezing episode noted in the medical record during the preceding 12 months should not receive FluMist. †† Two doses administered at least 4 weeks apart are recommended for children aged 2--8 years who are receiving LAIV for the first time, and those who only received 1 dose in their first year of vaccination should receive 2 doses in the following year.

BOX 1. Summary of seasonal influenza vaccination recommendations, 2009: children and adolescents aged 6 months--18 years
All children aged 6 months--18 years should be vaccinated annually. Children and adolescents at higher risk for influenza complications should continue to be a focus of vaccination efforts as providers and programs transition to routinely vaccinating all children and adolescents, including those who: are aged 6 months--4 years (59 months); have chronic pulmonary (including asthma), cardiovascular (except hypertension), renal, hepatic, cognitive, neurologic/neuromuscular, hematological or metabolic disorders (including diabetes mellitus); are immunosuppressed (including immunosuppression caused by medications or by human immunodeficiency virus); are receiving long-term aspirin therapy and therefore might be at risk for experiencing Reye syndrome after influenza virus infection; are residents of long-term care facilities; and will be pregnant during the influenza season.
Note: Children aged < 6 months cannot receive influenza vaccination. Household and other close contacts (e.g., daycare providers) of children aged < 6 months, including older children and adolescents, should be vaccinated.

BOX 1. Summary of seasonal influenza vaccination recommendations, 2009: children and adolescents aged 6 months--18 years

All children aged 6 months--18 years should be vaccinated annually.

Children and adolescents at higher risk for influenza complications should continue to be a focus of vaccination efforts as providers and programs transition to routinely vaccinating all children and adolescents, including those who:

are aged 6 months--4 years (59 months);
have chronic pulmonary (including asthma), cardiovascular (except hypertension), renal, hepatic, cognitive, neurologic/neuromuscular, hematological or metabolic disorders (including diabetes mellitus);
are immunosuppressed (including immunosuppression caused by medications or by human immunodeficiency virus);
are receiving long-term aspirin therapy and therefore might be at risk for experiencing Reye syndrome after influenza virus infection;
are residents of long-term care facilities; and
will be pregnant during the influenza season.

Note: Children aged < 6 months cannot receive influenza vaccination. Household and other close contacts (e.g., daycare providers) of children aged < 6 months, including older children and adolescents, should be vaccinated.

BOX 2. Summary of influenza vaccination recommendations, 2009: adults
Annual vaccination against influenza is recommended for any adult who wants to reduce the risk of becoming ill with influenza or of transmitting it to others. Vaccination is recommended for all adults without contraindications in the following groups, because these persons either are at higher risk for influenza complications, or are close contacts of persons at higher risk: persons aged 50 years and older; women who will be pregnant during the influenza season; persons who have chronic pulmonary (including asthma), cardiovascular (except hypertension), renal, hepatic, cognitive, neurologic/neuromuscular, hematological or metabolic disorders (including diabetes mellitus); persons who have immunosuppression (including immunosuppression caused by medications or by human immunodeficiency virus; residents of nursing homes and other long-term care facilities; health-care personnel; household contacts and caregivers of children aged <5 years and adults aged 50 years and older, with particular emphasis on vaccinating contacts of children aged <6 months; and household contacts and caregivers of persons with medical conditions that put them at higher risk for severe complications from influenza.

BOX 2. Summary of influenza vaccination recommendations, 2009: adults

Annual vaccination against influenza is recommended for any adult who wants to reduce the risk of becoming ill with influenza or of transmitting it to others. Vaccination is recommended for all adults without contraindications in the following groups, because these persons either are at higher risk for influenza complications, or are close contacts of persons at higher risk:

persons aged 50 years and older;
women who will be pregnant during the influenza season;
persons who have chronic pulmonary (including asthma), cardiovascular (except hypertension), renal, hepatic, cognitive, neurologic/neuromuscular, hematological or metabolic disorders (including diabetes mellitus);
persons who have immunosuppression (including immunosuppression caused by medications or by human immunodeficiency virus;
residents of nursing homes and other long-term care facilities;
health-care personnel;
household contacts and caregivers of children aged <5 years and adults aged 50 years and older, with particular emphasis on vaccinating contacts of children aged <6 months; and
household contacts and caregivers of persons with medical conditions that put them at higher risk for severe complications from influenza.