U.S. Influenza Activity and Vaccine Effectiveness Update Lisa Grohskopf, MD MPH Vaccine and Related Biologic Products Advisory Committee Meeting 28 February 2014 National Center for Immunization and Respiratory Diseases Influenza Division

Influenza Activity Update Lyn Finelli, DrPH, MS Influenza Surveillance and Outbreak Response Team Epidemiology and Prevention Branch Influenza Division ACIP February 26, 2013

VIROLOGIC SURVEILLANCE

U.S. World Health Organization and National Respiratory and Enteric Virus Surveillance System Collaborating Laboratories, National Summary,

Antiviral Resistance October 1, 2013 – February 15, 2014  High levels of resistance to the adamantanes (amantadine and rimantadine) persist among pH1N1 and influenza A (H3N2) viruses currently circulating globally. Neuraminidase Inhibitor Resistance Testing Results Samples Collected Since October 1, 2013 OseltamivirZanamivir Virus Samples tested (n) Resistant Viruses, Number (%) Virus Samples tested (n) Resistant Viruses, Number (%) Influenza A (H3N2) 1860 (0.0)1860 (0.0) Influenza B730 (0.0)730 (0.0) 2009 H1N13,47126 (0.7)1,2590 (0.0)

ILI SYNDROMIC SURVEILLANCE

Percentage of Visits for Influenza-like Illness (ILI) Reported by the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet), Weekly National Summary, and Selected Previous Seasons 6.1% 4.6%

HOSPITALIZATION SURVEILLANCE

Rates of Lab-Confirmed Influenza Hospitalization FluSurvNet, October 1, 2013 – February 15, /100K 41/100K 38/100K 18/100K 7/100K Overall Rate 26.1/100K pop

MORTALITY SURVEILLANCE

Number of Influenza-Associated Pediatric Deaths by Week of Death: to February 15, 2014

Epidemic Threshold Seasonal Baseline Pneumonia and Influenza Mortality 122 U.S. Cities Surveillance System National Summary, % 9.9%

Influenza Deaths by Age Group 122 Cities Mortality Reporting System, Number of Influenza Deaths by Age Group and Year * **Data as of week 6, 2014 ** *Data from week 15, 2009 – week 39, 2010

Influenza Activity Summary  Influenza activity in the US during the 2013–14 season began approximately 4 weeks earlier than usual, and occurred at moderate levels  Activity peaked in late December/early January  Influenza A (H1N1) viruses predominated  There are higher rates of influenza-associated hospitalization in in persons years of age than during the past several seasons  There were higher numbers of influenza deaths in the 122 Cities Mortality Surveillance System in in persons years than during past several seasons

Acknowledgements Joseph Bresee Scott Epperson Lenee Blanton Krista Kniss Rosaline Dhara Desiree Mustaquim Alejandro Perez Michelle Leon Andrea Giorgi Craig Steffens Ashley Fowlkes Julie Villanueva Sophie Smith Michael Jhung Carrie Reed Alicia Fry Seema Jain Anna Bramley Victoria Jiang Sandra Dos Santos Chaves Daniel Jernigan Joe Gregg Larissa Gubareva Terri Wallace Xiyan Xu Nancy Cox

Interim Estimates of Seasonal Influenza Vaccine Effectiveness — United States, February 2014 Data from the U.S. Flu VE Network December 2, 2013-January 23, 2014 Brendan Flannery, PhD Influenza Division Presentation to the ACIP Influenza Working Group February 18, 2014 National Center for Immunization & Respiratory Diseases Influenza Division

US Flu VE Network: Five Study Sites and Principal Investigators Lisa Jackson Mike Jackson Ed Belongia Arnold Monto Suzanne Ohmit Rick Zimmerman Patricia Nowalk Manju Gaglani

US Flu VE Network: Methods Enrollees: All persons aged >6 months with medically attended acute respiratory illness (MAARI) – ambulatory care visits from Dec 2, 2013-Jan 23, 2014 Methods : Prospective case-control study (test negative design)  Influenza infection confirmed with CDC RT-PCR  Cases: Outpatient ARI and influenza PCR-positive  Controls: Outpatient ARI and influenza PCR-negative  Vaccination status: receipt of ≥1 dose of seasonal flu vaccine confirmed by medical records and registries (2 sites) and self-report and medical records (3 sites) Analysis: VE = (1 – adjusted OR) x 100%  Adjustment for study site, age, sex, race/ethnicity, self-rated health and days from illness onset to enrollment

US Flu VE Network: Results Influenza test resultNo. (%) Influenza A778 (99%) H1N1pdm09742 H3N213 Not subtyped23 Influenza B6 (1%) 2,319 enrolled from 2 December, January, ,535 (66%) influenza RT-PCR negative 784 (34%) influenza RT-PCR positive

Adjusted VE* and 95% CIs against influenza A and B for ≥1 dose of seasonal influenza vaccine, by age group * Vaccine effectiveness was estimated as 100% X (1 – odds ratio [ratio of odds of vaccination among flu-positive cases to odds of vaccination among flu-negative controls]) using multivariable logistic regression including study site, age, sex, race/ethnicity, self-rated health status and days from illness onset to enrollment.

Comparison of adjusted VE estimates against H1N1pdm09 associated outpatient ARI over several influenza seasons * Adjusted VE and 95% CI for primary healthcare patients: 42% (-97%-83%). Source: Castilla J, Eurosurveillance 2014.

Conclusions  2009 H1N1pdm virus predominated among influenza viruses identified from Dec 2, 2013-Jan 23, 2014 in U.S.  Interim adjusted VE against H1N1pdm09 associated medically attended ARI = 62% (95% CI: 53-69)  Similar for all age groups  Similar to VE estimates from previous seasons  Consistent with laboratory data  Final analyses for season will investigate effects of prior vaccination  Ability to estimate VE for H3N2 or B infections will depend upon final sample size

US Flu VE Network University of Michigan and Henry Ford Health System : Arnold S. Monto, MD, Suzanne E. Ohmit, DrPH, Joshua G. Petrie, MPH, Emileigh Johnson, Rachel T. Cross, MPH, Casey Martens, Marcus Zervos, MD, Lois Lamerato, PhD, Mary Ann Aubuchon, William Fredrick; University of Pittsburgh Schools of the Health Sciences and UPMC : Richard K. Zimmerman, MD, Mary Patricia Nowalk, PhD, Jonathan M. Raviotta, MPH, Heather Eng, Stephen R. Wisniewski, PhD, Charles R. Rinaldo, Jr, MD, Arlene Bullotta, Joe Suyama, MD, Evelyn Reis, MD, Donald B. Middleton, MD, Rhett H. Lieberman, MD, Michael Susick, MPH, Krissy K. Moehling, MPH, Mallory Schaffer, BS; Baylor Scott and White Health, Texas A&M University Health Science Center College of Medicine : Manjusha Gaglani, Lydia Clipper, RN, Anne Robertson, AA, Kempapura Murthy, MPH, Monica Weir, Hope Gonzales, Martha Zayed, Teresa Ponder, Virginia Gandy, RN, Patricia Sleeth, RN, Sophia V James, MS,, Michael Reis, MD, Cathleen Rivera, MD, David Morgan, MD, and Baylor College of Medicine : Pedro Piedra, MD, Vasanthi Avadhanula, PhD; Group Health Research Institute : Michael L. Jackson, PhD, Lisa A. Jackson, MD, C. Hallie Phillips, MEd, Joyce Benoit, RN, Lawrence T. Madziwa, MS, Matt B. Nguyen, MPH, Julia P. Anderson, MA; Marshfield Clinic Research Foundation : Edward A. Belongia, MD, Huong Q. McLean, PhD, Deanna Cole, Donna David, Sarah Kopitzke, MS, Tamara A. Kronenwetter Koepel, Jennifer K. Meece, PhD, Carla Rottscheit, Sandra K. Strey, Maria E. Sundaram, MSPH, Laurel A. Verhagen; CDC: Alicia M. Fry, MD, Swathi N. Thaker, PhD, Jessie Clippard, MPH, Ivo Foppa, PhD, Jill Ferdinands, PhD, LaShondra Berman, MS, Angie Foust, MS, Wendy Sessions, MPH, Sarah Spencer, PhD, Erin Burns, MA, Joseph Bresee, MD, Nancy Cox, PhD.