Influenza > > Frequently Asked Questions

ACIP Recommendations for 2007 – 2008
Has ACIP changed their vaccination recommendations this year? Who is currently recommended for vaccination?
What are the recommendations for two doses of influenza vaccine for children under 9 years of age?
What are the current recommendations around vaccination of school aged children?

When is the best time to vaccinate?
The full text of ACIP's recommendations in the MMWR

Vaccine Composition and Information for 2007-2008
What vaccine strains are included in this year's vaccines?

Is thimerosal-free influenza vaccine available this season?

Trivalent Inactivated Influenza Vaccine (TIV) and Live Attenuated Influenza Vaccine (LAIV)
In what ways are TIV and LAIV similar?
What are the main differences between TIV and LAIV?
Who can be vaccinated with LAIV? When is LAIV a good choice?

Since LAIV is a live virus, what are the possibilities for transmitting infection to ill patients or family members?
What is the efficacy of TIV?
What is the efficacy of LAIV?

Influenza and Health Care Workers
Why is it important to vaccinate health care workers?
Who is considered a healthcare worker?
Are there restrictions on the use of live attenuated influenza vaccine (LAIV) in health care workers?
What are the new JCAHO infection control standards for accredited organizations?

ACIP Recommendations for 2007 – 2008

Has ACIP changed their vaccination recommendations this year? Who is currently recommended for vaccination?
The recommendations for who should seek influenza vaccine have not changed this year. The ACIP recommends vaccinating: ·

• All persons who want to reduce the risk of becoming ill with influenza or of transmitting influenza to others
• All children aged 6-59 months
• All persons aged >50 years
• Children and adolescents (aged 6 months-18 years) receiving long-term aspirin therapy who therefore 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), cardiovascular (except hypertension), renal, hepatic, hematological or metabolic disorders (including diabetes mellitus)
• Adults and children who have immunosuppression; including immunosuppression caused by medications or by human immunodeficiency virus
• Adults and children who have 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
• Residents of nursing homes and other chronic-care facilities
• Health-care personnel
• Healthy household contacts (including children) and caregivers of children aged <5 years and adults aged >50 years, with particular emphasis on vaccinating contacts of children aged <6 months
• Healthy household contacts (including children)and caregivers of persons with medical conditions that put them at higher risk for severe complications from influenza.

ACIP reemphasizes the importance of administering two doses of vaccine to all children aged 6 months through 8 years if they have not been vaccinated previously at any time with either LAIV (doses separated by >6 weeks) or TIV (doses separated by >4 weeks), on the basis of accumulating data indicating that two doses are required for protection in these children.
ACIP recommends that children aged 6 months through 8 years who received only one dose in their first year of vaccination receive two doses the following year.

ACIP reiterates a previous recommendation that all persons, including school-aged children, who want to reduce the risk of becoming ill with influenza or of transmitting influenza to others, should be vaccinated.
This year school districts in Columbia, Hood River, Jefferson, Linn, Marion, Tillamook, Washington, Wheeler and Yamhill counties will be hosting school-based “SchoolMist” clinics, offering FluMist to students. Please visit our website for more information onSchoolMist:

Vaccination efforts should be structured to ensure the vaccination of as many persons as possible over the course of several months, with emphasis on vaccinating as many persons as possible before influenza activity in the community begins. Even if vaccine distribution begins before October, distribution probably will not be completed until December or January. Vaccination efforts should continue throughout the season, because the duration of the influenza season varies, and influenza might not appear in certain communities until February or March. Providers should offer influenza vaccine routinely, and organized vaccination campaigns should continue throughout the influenza season, including after influenza activity has begun in the community. Vaccine administered in December or later, even if influenza activity has already begun, is likely to be beneficial in the majority of influenza seasons.

Where can I find the full text of ACIP's recommendations?
Online or view the MMWR

Return to top  
Vaccine Composition and Information for 2007-2008

What vaccine strains are included in this year's vaccines?
The 2007-2008 trivalent vaccine strains are A/Solomon Islands/3/2006 (H1N1)-like (new for this season), A/Wisconsin/67/2005 (H3N2)-like, and B/Malaysia/2506/2004-like viruses.

Thimerosal-free vaccine is in production by all manufacturers and an increased supply is anticipated this season. Sanofi pasteur produces thimerosal-free doses of influenza vaccine. Most will be in 0.25 mL prefilled syringes, indicated for children ages 6-35 months. The rest will be in 0.5 mL prefilled syringes or vials, indicated for people ages 3 years and up. GlaxoSmithKline's influenza vaccine, for people ages 18 and up, is preservative-free, and Novartis (formerly Chrion) has a preservative-free presentation for people ages 4 and older.
Flumist™, the intranasal influenza vaccine, is also thimerosal-free.

Return to top  

Trivalent Inactivated Influenza Vaccine (TIV) and Live Attenuated Influenza Vaccine (LAIV)

In what ways are TIV and LAIV similar?

• Both contain the same strains of influenza viruses.
• Both are grown in eggs.
• Both vaccines need to be administered annually to provide the best protection against influenza infection.

• TIV contains killed viruses and cannot produce signs or symptoms of influenza infection. LAIV contains live, attenuated viruses and has the potential to produce mild signs or symptoms of influenza infection.
• TIV is administered intramuscularly, and LAIV is administered intranasally.
• LAIV is approved only for use in healthy, nonpregnant people ages 5-49. TIV can be given to people ages 6 months and above, and includes healthy people and those with medical conditions.

LAIV can be given to healthy, nonpregnant people ages 5-49 years. This includes health care workers and family members who will be in close contact with people at high risk for severe complications to influenza infection. When TIV is in short supply, use of LAIV is encouraged for people who are eligible, because this may increase availability of TIV for people in high-risk groups. Advantages of LAIV include its potential to induce a broad mucosal and systemic immune response, ease of administration, and the acceptance of an intranasal, rather than intramuscular, route of injection.

Available data indicate that both children and adults vaccinated with LAIV can shed vaccine viruses after vaccination, although in lower amounts than occur typically with shedding of wild-type influenza viruses. In rare instances, shed vaccine viruses can be transmitted from vaccine recipients to non-vaccinated persons. However, serious illnesses have not been reported among unvaccinated persons who have been infected inadvertently with vaccine viruses.

The efficacy of TIV depends on age and immunocompetence of the vaccine recipient and the degree of match between influenza vaccine viruses and circulating influenza viruses.

• Children: In a study of children ages 1-15 years, influenza vaccine was 77% and 91% effective against influenza respiratory illness during H3N2 and H1N1 years, respectively. Vaccine effectiveness is lower for previously unvaccinated children 6 months to 9 years who receive only one dose of influenza vaccine, compared with previously unvaccinated children who receive the recommended two doses.
  
• Adults 18-64 years: Influenza vaccine is typically 70-90% effective in preventing influenza illness in healthy adults <65 years="years" age.="age." influenza="influenza" vaccination="vaccination" can="can" result="result" in="in" work="work" absenteeism="absenteeism" and="and" decreased="decreased" use="use" of="of" healthcare="healthcare" resources.</li ="resources.&lt;/li">
  
• Adults ages 65 years and above: Influenza vaccination can reduce the risk of influenza-related hospitalization and death among adults ages 65 years and above. In one study of older persons who reside in nursing homes, influenza vaccine was 30-40% effective in preventing influenza illness, 50-60% effective in preventing influenza-related pneumonia and hospitalization, and 80% effective in preventing influenza-related deaths.

¹CDC. Prevention and control of influenza: Recommendations of the Advisory Committee on Immunization Practices (ACIP). Early Release 2006:55 (June 28, 2006).

• Healthy Children: A review of LAIV effectiveness in children ages 18 months through 18 years demonstrated efficacy levels of 92% against influenza A (H1N1) and 66% against influenza B drift variant.
  
• Healthy Adults: One study demonstrated the overall efficacy of LAIV and TIV in preventing laboratory-documented influenza infection for all three influenza strains combined to be 85% and 71% respectively. This difference was not statistically significant.

To learn more about influenza vaccine efficacy, go to ACIP's Prevention and Control of Influenza, at our website:

Influenza and Health care workers

Why is it important to vaccinate health care workers?

Health care workers have close contact with high-risk patients; often serving as vectors for healthcare-associated influenza. Unvaccinated health care workers have contributed to influenza outbreaks in a variety of clinical settings, including neonatal intensive care units, pediatric wards, adult and pediatric transplant units, infectious disease units, oncology units, emergency departments, and more². These healthcare-associated outbreaks may result in increased patient morbidity and mortality, increased length of hospitalization, higher medical costs, and disruption of essential healthcare services.

²Talbot, T; Bradley, S; Cosgrove, S; Ruef, C; Siegel, J; and Weber, D. (2005, November). Position Paper: Influenza vaccination of health care workers and vaccine allocation for health care workers during vaccine shortages. Infection Control and Hospital Epidemiology. Vol. 26, No. 11, pg 882-890.

Vaccination of health care workers is a cornerstone in the prevention of influenza infection and is supported by the following groups:

• The Advisory Committee on Immunization Practices (ACIP)
• The Society for Healthcare Epidemiology of America (SHEA)
• The Joint Commission for the Accreditation of Healthcare Organizations (JCAHO)

• Physicians, nurses, and other workers in both hospital and outpatient-care settings, including medical emergency-response workers (e.g., paramedics and emergency medical technicians)
• Employees of nursing home and chronic-care facilities who have contact with patients or residents
• Employees of assisted living and other residences for persons in high-risk groups
• Providers of home care to people at high-risk (e.g., visiting nurses and volunteer workers)

LAIV transmission from a recently vaccinated person causing clinically important illness in an immunocompromised contact has not been reported. The rationale for avoiding use of LAIV among health care workers caring for such patients is the theoretic risk that a live, attenuated vaccine virus could be transmitted to the severely immunosuppressed person. As a precautionary measure, health care workers who receive LAIV should avoid providing care for severely immunosuppressed patients (i.e., hemopoetic stemm cell transplant recipients) for 7 days after vaccination.

The new JCAHO infection control standards require accredited organizations to offer influenza vaccine to staff, including volunteers and licensed independent practitioners with close patient contact.
As of January 2007, accredited organizations are required to:

• Establish an annual influenza vaccination program that includes at least staff and licensed independent practitioners
• Provide access to influenza vaccinations on-site
• Educate staff and licensed independent practitioners about influenza vaccination; non-vaccine control measures; and diagnosis, transmission, and potential impact of influenza
• Annually evaluate vaccination rates and reasons for non-participation in the organization's immunization program, and
• Implement enhancements to the program to increase participation.