Joseph Bresee, MD Epidemiology and Prevention Branch Influenza Division

1. Update on Influenza in the U.S.Disease circulation and vaccine and antiviral recommendations for the 2011-2012 Influenza Season Joseph Bresee, MD Epidemiology and Prevention Branch Influenza Division Centers for Disease Control and Prevention National Center for Immunization & Respiratory Diseases Influenza Division September, 2011

2. Epidemiology/SurveillanceU.S. WHO/NREVSS Collaborating Laboratories, National Summary, 2009-11

3. Epidemiology/SurveillancePercentage of Visits for Influenza-like Illness (ILI) Reported by the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet),National Summary October 1, 2006 – August 27, 2011

4. Epidemiology/SurveillancePneumonia and Influenza Mortality for 122 U.S. Cities -Week Ending 27 AUG 2011 Epidemic Threshold Seasonal Baseline 2011 2007 2008 2009 2010 2006

5. 2 cases of swine-origin trH3N2 virus infection (IN, PA) • Both aged 2 years old, had influenza-like illness, recovered • Epidemiologically unrelated • One case had indirect exposure (caretaker of chronically ill child had direct contact with well-appearing pigs) • One case visited an agricultural fair, had direct contact with pigs, other animals • 2 additional cases confirmed; investigations in-progress • trH3N2 reassortant viruses with M gene of 2009 H1N1 virus

6. Seasonal Influenza Impact in U.S. Vary substantially from year to year Difficult to predict severity or timing 5% - 20% of US population infected highest illness rates in childre Range of 3,349-48,614 (average 23,607) influenza-related deaths annually in the US 2.7 times higher when H3N2 prominent ~90% among 65 and older Recently updated 1976-2007 in MMWR (Aug 20, 2010) Annual average of 220,000 hospitalizations About 50% in 65 and older

7. Influenza Vaccine Primary means to prevent influenza and its complications Seasonal influenza vaccination recommended for all persons 6 months of age and older Primary means to protect <6 months is vaccination of household members and out-of-home caregivers Yearly updated vaccine strains and recommendations Recommendation for vaccination by a healthcare provider is a key factors in patients’ decisions to get vaccinated

8. Groups at Increased Risk of Severe Influenza • Children younger than 5 years old, but especially children younger than 2 years old • Persons aged 65 years and older • Pregnant women • American Indians and Alaska Natives • People who have medical conditions including: • Asthma • Neurological and neurodevelopmental conditions [including disorders of the brain, spinal cord, peripheral nerve, and muscle such as cerebral palsy, epilepsy (seizure disorders), stroke, intellectual disability (mental retardation), moderate to severe developmental delay, muscular dystrophy, or spinal cord injury]. • Chronic lung disease (such as chronic obstructive pulmonary disease [COPD] and cystic fibrosis) • Heart disease (such as congenital heart disease, congestive heart failure and coronary artery disease) • Blood disorders (such as sickle cell disease) • Endocrine disorders (such as diabetes mellitus) • Kidney disorders • Liver disorders • Metabolic disorders (such as inherited metabolic disorders and mitochondrial disorders) • Weakened immune system due to disease or medication (such as people with HIV or AIDS, or cancer, or those on chronic steroids) • People younger than 19 years of age who are receiving long-term aspirin therapy • People who are morbidly obese (Body Mass Index, or BMI, of 40 or greater)

9. Types Influenza Vaccines Inactivated vaccines Intramuscular injection First approved for used in 1945 in U.S. Used in persons >6 months old Different manufactures, including 1 with a high dose vaccine for adults 65 years and older Live, attenuated vaccines (LAIV) Licensed in U.S. 1999 Approved for healthy non-pregnant persons 2-49 years Persons at high risk of influenza-complications are not recommended to receive LAIV Health care personnel and contacts of high risk can take FluMist Only contraindicated in persons working with those who are so immune suppressed as to require a protected environment Both types Updated annually, yearly vaccination needed

10. 2011-2012 Vaccine Components • Vaccine virus strains same as those in the 2010-2011 vaccine: • A/California/7/2009 (H1N1)-like • A/Perth/16/2009 (H3N2)-like • B/Brisbane/60/2008-like • Since protection from vaccine has been shown to decline over time, annual vaccination is recommended for optimum protection against influenza, even in seasons in which vaccine virus strains do not change. • CDC recommends that you get vaccinated as soon as vaccine is available in your community

11. High-Dose vs Standard-Dose Influenza Vaccine Higher antibody titers compared with standard-dose vaccine significantly higher antibody responses to influenza A vaccine strains vs standard-dose TIV vaccine for people ≥65 years of age with or without underlying medical conditions1 With an increased dose, there was an associated increase in injection-site reactogenicity Most injection-site and systemic reactions were mild and resolved within 72 hours Fluzone High Dose (sanofi-pasteur) US FDA approval – December 2009 Option for US adults 65 years and older • Falsey A, et al. J Infect Dis. 2009;200:172-180.

12. Intradermal Influenza Vaccine • A new intradermally-administered TIV, Fluzone Intradermal® (sanofi pasteur) licensed in May 2011 • Indicated for persons aged 18-64 years • Contains less antigen than regular intramuscular TIV preparations (9 mcg per strain instead of 15 mcg), but similarly effective in inducing immune response • Administered intradermally via a single-dose, prefilled microinjection syringe • Smaller volume than other TIV preparations • Is an alternative to other seasonal vaccines for the indicated age group • No preferential recommendation *TIV= trivalent inactivated vaccine

13. Influenza Vaccine Dosing for Children 6 Months Through 8 Years of Age Did the child receive ≥1 dose of the 2010-2011 seasonal influenza vaccine? No/Not Sure Administer 2 doses this season* Yes Administer 1 dose this season *Doses should be administered a minimum of 4 weeks apart

14. Influenza Vaccination of Persons with Egg Allergies • All currently available influenza vaccines are produced in chickens’ eggs • Final vaccine product contains a small amount of residual egg protein, posing some risk of allergic reaction in susceptible individuals • Influenza vaccine package inserts in the past have included “hypersensitivity” to egg as a contraindication of receipt of vaccine • Relatively general term including reactions of all severities • However, several studies of use of TIV indicate that egg-allergic persons with a history of less severe reactions to egg (hives) can receive vaccine safely

15. Influenza Vaccination of Persons with Egg Allergies • Individuals who have experienced only hives following exposure to egg should receive influenza vaccine with the following additional measures: • As studies published to date involved use of TIV, TIV rather than LAIV should be used; • Vaccine should be administered by a healthcare provider who is familiar with the potential manifestations of egg allergy; and • Vaccine recipients should be observed for at least 30 minutes for signs of a reaction following administration of each vaccine dose • Those with more severe reactions to egg (e.g., anaphylaxis) should receive further risk assessment from a clinician with expertise in management of allergic conditions before receipt of vaccine • All vaccines should be administered in settings where personnel and equipment needed for rapid recognition and treatment of anaphylaxis are available

16. Vaccinating pregnant women • Pregnant women are at high-risk of severe disease and complications • Vaccine has been promoted as the best way to protect them • Vaccine is safe in pregnant women • Recent studies have shown that vaccinating pregnant women can protect their infants from influenza as well • Since infants < 6 months can’t be vaccinated themselves, vaccinating their mothers during pregnancy, and their family members can protect them from infection • Vaccinated mothers pass protective antibodies to their babies through the placenta • Vaccinating household members reduces the chance to transmitting the virus to young infants from infected household members

17. Antiviral Agents for Treatment and Chemoprophylaxis of Influenza . Influenza Division National Center for Immunization & Respiratory Diseases

18. ACIP Statement on Antiviral Agents for the Treatment and Chemoprophylaxis of Influenza MMWR 2011, Volume 60 (#RR-1) January 21, 2011

19. Guidance for Antiviral Agents, 2010-2011 • Oseltamivir or zanamivir for influenza A (all subtypes) and B virus infections • Empiric antiviral treatment is recommended as early as possible for any patient with confirmed or suspected influenza who: • has severe, complicated, or progressive illness, or • requires hospitalization, or • is at higher risk for influenza complications, or • is non high-risk if early treatment can be given based on clinical judgment • Initiation of therapy should not be delayed (while waiting for results of diagnostic testing) if clinically indicated ACIP Guidance for Use Antiviral Agents http://www.cdc.gov/flu/professionals/antivirals/guidance/ Updates on antiviral resistance can be found at: http://www.cdc.gov/flu/weekly/

20. Summary of Antiviral Resistance Among Influenza Viruses Worldwide, December 2010 Source: MMWR 2011, Volume 60 (#RR-1), p.7, Table 2

21. Influenza levels low, but expected to increase during the Fall . Perfect time to get vaccinated People with chronic medical conditions are at higher risk of severe complications from influenza, including hospitalization and death Many people in these groups do not realize that their medical conditions increase their risk Universal vaccine recommendation will encourage everyone to get vaccinated - will increase coverage among close contacts of people with high risk conditions Appropriate antiviral use encouraged as an adjunct to vaccination Key Points