Thursday, September 14, :00 AM ET. Overview. Creating Flu Vaccines: Strain Selection. Assessing Vaccine Effectiveness

Transcription

1 Influenza (Flu) 101 Thursday, September 14, :00 AM ET Introduction Overview Creating Flu Vaccines: Strain Selection Assessing Vaccine Effectiveness Monitoring the Season: Flu Surveillance Flu Myths & Misperceptions 2 1

2 Speakers Moderator: William Schaffner, MD NFID Medical Director Professor of Preventive Medicine and Infectious Diseases Vanderbilt University School of Medicine Nashville, TN Jacqueline Katz, PhD Deputy Director, Influenza Division NCIRD, CDC Atlanta, GA Brendan Flannery, PhD Epidemiologist Epidemiology and Prevention Branch, Influenza Division NCIRD, CDC Atlanta, GA Alicia P. Budd, MPH Epidemiologist, Epidemiology and Prevention Branch Influenza Division NCIRD, CDC Atlanta, GA 3 General Information Please note that today s webinar is being recorded All phone lines will be placed on mute throughout the program To hear audio: Computer: Follow directions Phone: ; Access Code After the presentations, there will be a Question and Answer period Use the Chat box on the lower left side of your screen to type your question At the end of the webinar, participants will be directed to an online evaluation Following the webinar, all registered participants will receive an with a link to the presentation slides 4 2

3 About NFID Non-profit 501(c)(3) organization dedicated to educating the public and healthcare professionals about causes, treatment, and prevention of infectious diseases across the lifespan Reaches consumers, healthcare professionals, and media through: Coalition-building activities Public outreach initiatives Professional educational programs (ACCME accredited with commendation) Scientific meetings, research, and training Longstanding partnerships to facilitate rapid program initiation and increase programming impact Flexible and nimble organization 5 Creating Flu Vaccines: Strain Selection Click to edit Master subtitle style Jacqueline Katz, PhD Deputy Director, Influenza Division, Centers for Disease Control and Prevention (CDC) Director, WHO Collaborating Center for Surveillance, Epidemiology and Control of Influenza 3

4 WHO Global Influenza Surveillance and Response System (GISRS) Conducts Year-Round Surveillance for Seasonal and Novel Influenza Viruses CDC is one of five WHO Collaborating Centers monitoring seasonal influenza viruses 7 Timelines of Annual Influenza Vaccine Production: Northern Hemisphere Jan. - May Jun. - July July Aug. Sept.- Dec. WHO recommendations Produce CVVs Vaccine Seeds Potency Reagents 8 4

5 Virological Surveillance is Focused on the Influenza Virus Hemagglutinin (HA) Surface Protein RBS Sugars Neuraminidase (NA) Enables virus entry into respiratory tract cells Main antigen and target of human immune response Antibodies to HA can block virus infection Changes in HA can result in antigenic drift and reduced protection from vaccines 9 The HA antigens stimulate serum antibodies in infected hosts These antibodies are used to evaluate how related one virus is to another Circulating viruses are compared with reference vaccine viruses Viruses can be mapped by antigenic cartography using data from serologic tests Antigenic Characterization Distances of 8-fold or greater identify antigenic drift viruses 10 5

6 Cumulative No. of Vaccine Component Changes /14/2017 Genetic Characterization Influenza viruses are constantly changing their genetic make-up Genetic sequence analysis is used to track the evolution of influenza viruses from season to season Changes in the HA (and NA) genes can result in changes in protein structures True antigenic drift viruses are those that have signature genetic changes that are associated with substantial antigenic changes 11 Challenge: A(H3N2) Viruses Properties and Low VE More frequent changes in H3N2 viruses Antigenic drift-need for more vaccine updates Receptor binding properties that affect ability to perform antigenic analyses Antigenic drift associated with reduced vaccine effectiveness H3N H1N

7 Percent of H3N2 Low Reactors 9/14/2017 Challenge: Drifted Viruses Can Emerge After WHO Recommendation 80% H3N2 Low Reactors by Hemagglutination Inhibition Testing, to Seasons 70% 60% 50% 40% 30% 20% 10% 0% Challenge: Generating Acceptable Egg-Adapted Vaccine Viruses for Manufacturing Virus Culture in Cells Cell-Propagated Virus Results in genetic changes that can affect antigenic properties Egg-Propagated Virus Virus Culture in Eggs Difficult to obtain egg isolates, especially for H3N2 viruses Egg-Adapted Vaccine Reassortant PR8 Vaccine Virus 14 7

8 Seasonal Influenza Vaccine Improvement (SIVI), an Interagency Initiative Multiple activities, including improving: Surveillance and Virus Collection Expanding global virus surveillance in GISRS Virus Characterization New Assays and wide use of Next-Gen sequencing to expand available data Apply to predictive models Candidate Vaccine Viruses (CVV) Increasing capacity and using synthetic biology Obtain cell-based CVVs for use in cell-based vaccine platform(s) Improved methods to test vaccine potency/release New vaccines 15 Assessing Vaccine Effectiveness How Well Does the Flu Vaccine Work? Click to edit Master subtitle style Brendan Flannery, PhD Lead for US Flu Vaccine Effectiveness (VE) Network Influenza Division, Centers for Disease Control and Prevention (CDC) 8

9 US Flu Vaccine Effectiveness (VE) Network and Principal Investigators Kaiser Permanente Washington Health Research Institute Mike Jackson Lisa Jackson Marshfield Clinic Research Institute Ed Belongia Huong McLean University of Michigan Arnold Monto Emily Martin University of Pittsburgh Rick Zimmerman Tricia Nowalk Baylor Scott & White Health Manju Gaglani CDC Brendan Flannery Alicia Fry 17 US Flu VE Network Methods Enrollees: Outpatients age >6 months with acute respiratory illness with cough 7 days duration Design: Test-negative case-control design Compares proportions of patients with influenza among vaccinated versus unvaccinated enrollees Patients are asked if they received flu vaccine and doses are documented in medical records or immunization records Analysis: Fewer flu cases among vaccinated enrollees indicates that flu vaccine has reduced risk of flu Accounts for differences in flu vaccination by study location, age, sex, race/ethnicity, underlying medical conditions and other factors 18 9

10 Flu Vaccine Effectiveness During Season Over 7000 enrolled; 28% tested positive for flu Vaccine effectiveness was 42%, within interval of 35%-48% Interpretation: Vaccinated people were about 40% less likely than unvaccinated people to have flu resulting in a healthcare visit during the flu season (roughly December-April) Over the past 10 years, estimates of flu VE have ranged from 19% (during ) to 60% (in ) 19 Does Flu Vaccine Effectiveness Vary by Influenza Virus Type? flu VE was 34% against predominant A(H3N2) virus VE was 56% against influenza B viruses, and 54% against A(H1N1) Consistent with lower VE against A(H3N2) viruses Recent analysis of VE studies1 from found VE of 33% (range 26%-39%) against A(H3N2) VE of 61% (57%-65%) against A(H1N1) viruses (since 2009) VE of 54% (46%-61%) against B viruses 1 Belongia et al, Variable influenza vaccine effectiveness by subtype: a systematic review and meta-analysis of test-negative design studies. Lancet Infectious Diseases

11 Vaccine Effectiveness in Older Adults VE was 25% (-5% to 46%) among people age 65 years and older VE was also low (19%) among adults age years VE among children age <1 to 8 years was 61% Analysis of VE over 5 seasons ( ) showed similar protection among adults age years and seniors (65+ years) Protection extended to older adults age 75+ years Even with low VE, vaccination prevents large number of flu-associated hospitalizations and deaths in elderly 21 Estimated Annual Number of Influenza Illness Averted with Vaccination Averted Illnesses Averted Medical Visits Averted Hospitalizations Averted Deaths to million million 39,300 86,700 1,230 3, million 2.7 million 61,500 1,820 1 Deaths with cause listed as pneumonia or influenza 2 An H3N2 predominant season with vaccine effectiveness similar to what was estimated for

12 Monitoring the Season: Influenza Surveillance in the United States Click to edit Master subtitle style Alicia P. Budd, MPH Epidemiology and Prevention Branch, Influenza Division National Center for Immunization and Respiratory Diseases (NCIRD) Centers for Disease Control and Prevention (CDC) Goals of Influenza Surveillance Identify and characterize viruses/strains Identify viruses with pandemic potential Provide situational awareness Describe the onset and duration of the season Track geographic spread Monitor severity Describe clinical infections and those at risk Guide decisions for interventions 24 12

13 US Influenza Surveillance National influenza surveillance is a collaborative effort CDC Influenza Division coordinates the system State and local public health staff are our primary partners Influenza surveillance coordinator in every state, Chicago, DC, NYC, Puerto Rico, US Virgin Islands, Palau, Mariana Islands Public health laboratorian in all states, NYC, DC Data providers Clinicians Vital statistics staff Laboratorians 25 US Influenza Surveillance System 26 13

14 US Influenza Surveillance Reports 27 Reporting and Analysis Timeline 28 14

15 Virologic Surveillance: (1) US World Health Organization (WHO) Collaborating Laboratories, (2) National Respiratory and Enteric Virus Surveillance System Laboratories (NREVSS), (3) Novel Influenza A Virus Reporting ~400 participating laboratories ~100 public health laboratories ~300 clinical laboratories Weekly reports # specimens tested # positive for influenza by type, subtype Age data from WHO collaborating labs Data Uses/Interpretation Is influenza activity increasing/decreasing and where? Distribution of circulating viruses A vs B; influenza A subtypes and B lineages Identification of viruses with pandemic potential (novel influenza A virus surveillance) 29 Influenza Positive Tests Reported to CDC by US Clinical and Public Health Laboratories, Season Clinical Laboratories Public Health Laboratories 30 15

16 Viral Strain Surveillance Public health labs submit subset of influenza positives to CDC for additional testing Full genome sequencing of all specimens Detailed antigenic characterization Antiviral resistance testing Development of vaccine candidate strains as needed Data Uses/Interpretation Monitor influenza virus evolution Guide decisions about antiviral use and vaccine strain selection 31 Outpatient Influenza-Like Illness (ILI) Surveillance: ILINet Primary care providers (~2,500) >35 million patient visits per season Weekly reports # of patient visits for ILI # patient visits for any reason Data Uses/Interpretation Is ILI (% of all visits that are for ILI) increasing/decreasing and where? How does this season compare to previous season in terms of weeks with elevated activity, timing of increased activity and intensity of peak? 32 16

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18 Hospitalization Surveillance: FluSurv-Net Population-based surveillance for laboratory-confirmed influenza-related hospitalizations 13 states (70 counties) ~ 9% US population under surveillance Weekly reports # of patients admitted to the hospital that have a positive laboratory test for influenza and reside in the catchment area Clinical/demographic information Data Uses/Interpretation How does rate of influenza hospitalizations compare to previous seasons? Are there changes to expected age/underlying condition/clinical characteristics?

19 Mortality Data: National Center for Health Statistics (NCHS) National Vital Statistics Death certificate data >99% of deaths occurring in the United States Preliminary data available as NCHS mortality surveillance data Daily updates of reports from state vital statistics office # of total deaths, pneumonia deaths and influenza deaths > 50% of expected deaths available at time of report (2 week lag) Data Uses/Interpretation Compare timing and severity of influenza impact on mortality (% of deaths due to pneumonia and influenza) to previous seasons 37 Influenza-Associated Pediatric Mortality Influenza-associated death in a person <18 years of age Requires laboratory confirmation of influenza Clinical and epidemiologic data Nationally notifiable condition since season Data Uses/Interpretation Are the number of reported deaths similar to previous seasons? Does clinical/epidemiologic data show anything new about risk factors/clinical course? 38 19

20 39 Summary National influenza surveillance in the US: Is a multi-component system that provides indicators of where, when, and to what extent influenza activity is occurring and which viruses are responsible for that activity Requires participation of many partners in healthcare and public health Is NOT trying to count every case of influenza or influenza-related illness Data from each component is analyzed/reported in way that most appropriately allows comparison from season to season Can only compare case counts for novel influenza A and pediatric death Has the ultimate goal of providing data needed to guide public health and clinical decision making in order to minimize the impact of influenza 40 20

21 Flu Myths & Misperceptions Click to edit Master subtitle style William Schaffner, MD NFID Medical Director Flu Myths & Misperceptions Common Myths About Flu MYTH: Vaccines can be dangerous and have adverse health effects MYTH: The flu vaccine can cause a person to get sick from the flu MYTH: Flu vaccination is not necessary each year MYTH: Healthy people don t need a flu vaccine MYTH: The flu is nothing more than just a bad cold or stomach flu MYTH: There is nothing a person can do if they get the flu 42 21

22 Vaccines Are Safe Vaccines can be dangerous and have adverse health effects Vaccines are safe. Zero studies have demonstrated evidence of major safety concerns associated with USrecommended childhood immunizations, which protect against 14 deadly, vaccine-preventable diseases in September; will be formally launched to NFID partners organizations and via Files/2013/Childhood-Immunization- Schedule/ChildhoodImmunizationScheduleandSafety_RB.pdf 43 You Cannot Get The Flu From The Flu Vaccine The flu vaccine can cause the flu Flu vaccines given with a needle are currently made in two ways: the vaccine is made either with flu vaccine viruses that have been inactivated and are therefore not infectious, or with no flu vaccine viruses at all (recombinant influenza vaccine) It typically takes two weeks after flu vaccination for the vaccine to become effective. It is possible that within those two weeks an individual not yet fully protected by the vaccine can develop influenza. That s why it is important for people to get vaccinated as soon as the vaccine is available

23 It s Important To Get Vaccinated Each Year Flu vaccination is not necessary each year CDC recommends annual vaccination for everyone older than 6 months. Immune protection from the flu vaccine declines over time, so annual vaccination is critical to provide the best protection. Because the vaccine changes each year to match the circulating flu viruses, each year s vaccine could be different from the last 45 Get Vaccinated No Matter How Healthy You Are Healthy people don t need a flu vaccine Even healthy people are at risk for getting sick from influenza. Because immunity to the vaccine weakens over time, getting vaccinated every year is important, regardless of how healthy a person is

24 Influenza Is Serious The flu is nothing more than just a bad cold or stomach flu Influenza is distinct from a bad cold or stomach flu it s more serious, and in mild cases causes high fever, head and body aches, coughing for days, and severe fatigue for up to two weeks or more. Unlike many other viral respiratory infections, such as the common cold, the flu can also cause severe illness and life threatening complications. While the numbers vary, in the US, millions of people are sickened, hundreds of thousands are hospitalized, and thousands or tens of thousands of people die from flu every year Treating Influenza: You Have Options There is nothing a person can do if they get the flu Prescription antiviral drugs can make the illness milder, alleviate symptoms faster, and may also prevent serious influenza complications A doctor can provide specific information about treatment options. Studies show that flu antiviral drugs work best for treatments when they are started within 2 days of getting sick. However, starting them later can still be helpful, especially if the sick person has a high-risk health condition or is very sick from the flu (for example, hospitalized patients)

25 Questions? Additional Resources