9/12/2018. Influenza and Influenza Vaccines. Influenza. Influenza Virus. Highly infectious viral illness. First pandemic in 1580

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1 Centers for Disease Control and Prevention National Center for Immunization and Respiratory Diseases Influenza and Influenza Vaccines Adult Track Photographs and images included in this presentation are licensed solely for CDC/NCIRD online and presentation use. No rightsare implied or extended for use in printing or any use by other CDC CIOs or any external audiences. Influenza Highly infectious viral illness First pandemic in 1580 At least 4 pandemics in 19th century Pandemics of 1957 and 1968 of lesser severity Most recent pandemic (H1N1) in Estimated 21 million deaths worldwide in pandemic of Virus first isolated in 1933 Influenza Virus Single-stranded RNA virus Orthomyxoviridaefamily 3 types: A, B, C Subtypes of type A are determined by hemagglutinin and neuraminidase 1

2 Influenza Virus Strains Type A Moderate to severe illness All age groups Humans and other animals Type B Milder epidemics Primarily affects children Humans only Type C Rarely reported in humans No epidemics Influenza Type A Subtypes Subtypes of type A determined by hemagglutinin (H) and neuraminidase (N) A/California/7/2009 (H1N1) Virus type Geographic origin Strain number Year of isolation Virus subtype Influenza Antigenic Changes Antigenic Drift Minor change, same subtype Caused by point mutations in gene May result in epidemic Antigenic Shift Major change, new subtype Caused by exchange of gene segments May result in pandemic 2

3 Influenza Pathogenesis Respiratory transmission of virus Replication in respiratory epithelium with subsequent destruction of cells Viremia rarely documented Virus shed in respiratory secretions for 5-10 days Influenza Clinical Features Incubation period: 2 days (range: 1-4 days) 50% of infected persons develop classic symptoms Abrupt onset of fever (usually F), myalgia, sore throat, nonproductive cough, headache 3

4 Influenza Complications Pneumonia Primary influenza pneumonia Secondary bacterial pneumonia Reye syndrome Myocarditis Death reported in <1 per 1,000 cases Impact of Influenza United States, Number of influenza-associated deaths varies substantially by year, influenza virus type and subtype, and age group Annual influenza-associated deaths ranged from 3,349 ( season) to 48,614 ( season), average of 23,607 annual deaths Updated estimates from to , deaths ranged from 12,000 (during ) to 56,000 (during ). Persons 65 years of age and older account for ~90% of deaths 2.7 times more deaths during seasons when A(H3N2) viruses were prominent Impact of Influenza--United States Highest rates of complications and hospitalizations among persons 65 years and older, young children, and persons of any age with certain underlying medical conditions Average of >200,000 influenza-related excess hospitalizations 37% of hospitalizations among persons younger than 65 years of age Greater number of hospitalizations during years that A(H3N2) is predominant 4

5 Influenza Epidemiology Reservoir Human, animals (type A only) Transmission Respiratory, probably airborne Temporal pattern Peak December March in temperate climate May occur earlier or later Communicability 1 day before to 5 days after onset (adults) Influenza Diagnosis Clinical and epidemiological characteristics Isolation of influenza virus from clinical specimen (e.g., throat, nasopharynx, sputum) Significant rise in influenza IgG by serologic assay Influenza Virus Testing Methods Method Types Detected Test Time Viral tissue cell culture A and B 3-10 days Rapid cell culture (shell vials; cell mixtures; yields live virus) A and B Immunofluorescence, Direct (DFA) or Indirect (IFA) Fluorescent Antibody Staining A and B Reverse transcriptase polymerase chain reaction (RT-PCR)and other molecular assays (influenza viral RNA or nucleic acid detection) Rapid molecular assay (influenza viral RNA or nucleic acid detection) A and B A and B 1-3 days 1-4 hours Varies by assay (generally minutes and 4-8 hours) Approximately 20 minutes Rapid influenza diagnostic tests (antigen detection) A and B <15 minutes Adapted from 5

6 Inactivated Influenza Vaccine Efficacy About 33% effective among healthy persons younger than 65 years of age 50-60% effective in preventing hospitalization among elderly persons 80% effective in preventing death among elderly persons 6

7 Influenza and Complications Among Nursing Home Residents *Inactivated influenza vaccine. Genesee county, MI, Influenza Vaccine Recommendations Abbreviations IIV = Inactivated influenza vaccine LAIV = Live, attenuated influenza vaccine RIV = Recombinant influenza vaccine Prefixes: SD = standard dose HD = high dose a = adjuvanted cc = cell-culture-based Numeric suffixes (e.g., RIV3, IIV4) indicate trivalent or quadrivalent, respectively 7

8 ACIP Influenza Statement--Overview Published in the MMWR August 24, 2018 Format same as last season MMWR focuses on recommendations and selected references; contains figure and main tables Supplemental materials (available from ACIP and Influenza Division web pages): Background Document with additional references 4-page summary of recommendations Core recommendation remains the same: Annual influenza vaccination is recommended for all persons aged 6 months who do not have contraindications Some Things That are thesamefor ) Groups Recommended for Vaccination Groups Recommended for Vaccination Routine annual influenza vaccination is recommended for all persons 6 months of age who do not have contraindications While vaccination is recommended for everyone in this age group, there are some for whom it is particularly important: People age 6 months who are at high risk of complications and severe illness Contacts and caregivers of these people, and of infants under age 6 months (because there is no vaccine approved for children this age) 8

9 Groups at Increased Risk for Influenza Complications and Severe Illness Children age 6 through 59 months and adults age 50 years (children under 6 months of age are also at high risk, but cannot be vaccinated) Persons with chronic pulmonary (including asthma) or cardiovascular (except isolated hypertension), renal, hepatic, neurologic, hematologic, or metabolic disorders (including diabetes mellitus) Immunosuppressed persons Women who are or will be pregnant during the influenza season Children and adolescents (age 6 months 18 years) who are receiving aspirin therapy and who might be at risk for experiencing Reye syndrome after influenza virus infection Residents of nursing homes and other long-term care facilities American Indians/Alaska Natives Persons who are extremely obese (BMI 40) Some Things That are thesamefor ) There are many influenza vaccines available There are Still Many Different Vaccines 13 distinct products for expected for (still a lot) More than one available vaccine might be appropriate for any recipient ACIP/CDC express no preferences for any one influenza vaccine over another Vaccination should not be delayed in order to obtain a specific product. 9

10 Inactivated (IIV) vs. Recombinant (RIV) vs. Live Attenuated (LAIV) IIVs: Contain inactivated virus, split or subunit Many brands, some for those as young as age 6 months (but approved ages vary!) All for are intramuscular Trivalent (1 B virus) or quadrivalent(2 B viruses) Standard Dose (15 μg of HA per virus) or high dose (60 μg of HA per virus) Unadjuvanted or adjuvanted Egg-or cell culture-based RIV4: Contains recombinant HA egg-free Recombinant HA made using insect cell line All quadrivalent LAIV4: Live attenuated, cold-adapted virus Egg-based All quadrivalent Quadrivalent vs. Trivalent IIV3, HD-IIV3, aiiv3 Contain an A(H1N1) virus, an A(H3N2) virus, and a B virus (from one lineage) IIV4, RIV4, LAIV Contain an A(H1N1) virus, an A(H3N2) virus, and 2 B viruses (one from each lineage) Designed to provide broader protection by representing both B lineages No preference expressed for trivalent or quadrivalent Egg-Based vs. non Egg-Based For most influenza vaccines, viruses are propagated in eggs. Two exceptions: cciiv4 (Flucelvax): Viruses are propagated in canine kidney cells rather than eggs However, one of the four initial viruses supplied to the manufacturer is eggderived (for , the H1N1 is still egg-derived), so not considered egg-free RIV4 (Flublok): Licensed for ages 18 years HA is produced without viruses, in an insect cell line Considered egg-free Better efficacy compared to an SD-IIV4 in a single-season randomized trial of ~8,600 participants aged 50 years No preference expressed for egg-based vs. non-egg-based vaccines Egg allergic persons can receive egg-based vaccines 10

11 High-Dose vs. Standard-Dose (IIVs Only) SD-IIV3 and 4: Contain 15μg of HA total per virus (45μg total for trivalents and 60μg total for quadrivalents) HD-IIV3 (FluzoneHigh-Dose): Licensed for ages 65 years Contain 60μg of HA total per virus (180μg total). Observed to provide stronger immune response in persons aged 65 years In several studies, HD-IIV3 demonstrated better efficacy/effectiveness comparedwithsd-iiv3 in this age group, including one large (nearly 32,000 participants) two-season randomized trial No preference expressed for HD-IIV3 or SD-IIVs ACIP Influenza Statement Updates Principal changes and updates for Influenza vaccine composition for LAIV4 an option for Vaccines for egg-allergic persons Key Updates for ) Composition of U.S. influenza Vaccines for

12 Influenza Vaccine Composition Trivalent vaccines: an A/Michigan/45/2015 (H1N1)pdm09-like virus; an A/Singapore/INFIMH /2016 (H3N2)-like virus; and a B/Colorado/06/2017-like virus (Victoria lineage). Quadrivalentvaccines: The above three viruses, and a B/Phuket/3073/2013-like virus (Yamagata lineage). Key Updates for ) LAIV4 is an option in LAIV4 Recommendations for Can choose any licensed, appropriate vaccine (IIV, RIV4, or LAIV4) LAIV had not been recommended for or Low effectiveness against influenza A(H1N1)pdm09 among children aged 2 through 17 yrs during and Thought due to poor fitness of the H1N1pdm09 virus in the vaccine In February 2018, ACIP reviewed additional data Two analyses of previous seasons data from observational studies: Manufacturer data on shedding and immunogenicity of LAIV New H1N1pdm09 virus showing better fitness For , LAIV4 is an option for those for whom it is appropriate No U.S. VE data yet on new formulation with the new H1N1pdm09 12

13 Who Shouldn t Receive LAIV4 (Contraindications) Persons aged <2 years or >49 years Labeled contraindications in package insert: History of severe allergic reaction to any vaccine component* or to a previous dose of influenza vaccine (like other flu vaccines) Note though that ACIP recommends vaccination of persons with egg allergy Concomitant aspirin-or salicylate-containing therapy in children or adolescents (risk of Reye syndrome) In addition, ACIP recommends LAIV not be used for Pregnant women Immunocompromised persons Children <5 with asthma or wheezing Caregivers and contacts of persons requirement a protected environment Persons who have received influenza antivirals within previous 48 hours Precautions to use of LAIV4 Similar to other influenza vaccines Moderate of severe illness with or without fever Guillain-Barré syndrome within 6 weeks following a previous dose of influenza vaccine Additional precautions specific to LAIV4 Asthma in persons aged 5 and older Other medical conditions that predispose to increased risk of severe influenza illness Key Updates for ) Influenza vaccination and persons with a history of egg allergy 13

14 Influenza Vaccination of Persons with Egg Allergy Mostly unchanged from last few seasons Main change is that LAIV4 is an option Egg allergic persons can receive any licensed, recommended vaccine that is otherwise appropriate (IIV, RIV4, or LAIV4) However, RIV not licensed for persons under 18 years of age For persons with a history of severe allergic reaction to egg (i.e., any symptom other than hives) The selected vaccine should be administered in an inpatient or outpatient medical setting (including but not necessarily limited to hospitals, clinics, health departments, and physician offices). Vaccine administration should be supervised by a health care provider who is able to recognize and manage severe allergic conditions. No specific post-vaccination observation period recommended However, per the ACIP General Best Practices guidelines, providers should consider observing all recipients of any vaccine for 15 minutes to avoid injury due to syncope Summary Still a good number of different influenza vaccines available Age indications differ No preferences for any one product over another LAIV4 is an option for those for whom it is appropriate for Not recommended for some groups, as previously Can be given to egg-allergic recipients of otherwise appropriate Now three different IIVs available for 6-through 35-month-olds But dose volumes differ! Inactivated Influenza Vaccine (IIV) and RIV Contraindications and Precautions Severe allergic reaction (e.g., anaphylaxis) to a vaccine component or following a prior dose of inactivated influenza vaccine Moderate or severe acute illness History of Guillain-Barré syndrome (GBS) within 6 weeks following a previous dose of influenza vaccine 14

15 Influenza Vaccine Adverse Events IIV Local reactions common Guillain-Barré syndrome (GBS) -expected to be greater among persons with a history of GBS than among persons with no history of GBS LAIV Nonspecific systemic symptoms -common Inactivated Influenza Vaccine (IIV) Adverse Reactions Local reactions (soreness, redness) 15% 20% Fever, malaise, myalgia Less than 1% Allergic reactions (hives, angioedema, anaphylaxis) Rare Timing of Vaccination Vaccination should occur before onset of influenza activity. Health care providers should offer vaccination by the end of October, if possible Children aged 6 months through 8 years who require 2 doses should receive their first dose as soon as possible after vaccine becomes available, and the second dose 4 weeks later Vaccination should continue to be offered as long as influenza viruses are circulating and unexpired vaccine is available To avoid missed opportunities for vaccination, providers should offer vaccination during routine health care visits and hospitalizations when vaccine is available 15

16 Vaccine Administration Inactivated Influenza Vaccine (IIV) Route: IM injection Needle gauge: gauge Needle length * : inch depending on the patient s age and/or weight IM injection Site: 6 months through 11 months: Vastuslateralismuscle 1 through 2 years: Vastuslateralismuscle is preferred; deltoid muscle may be used if the muscle mass is adequate 3 years and older: Deltoid muscle is preferred; vastus lateralis muscle may be used Note: FluzoneIntradermal is administered using a manufacturer-filled microinjection system in the deltoid area of the upper arm Vaccine administration error: Wrong dosage Wrong product outside of age indications Influenza Antiviral Agents* Amantadine and rimantadine Not recommended because of documented resistance in U.S. influenza isolates Zanamivirand oseltamivir Neuraminidase inhibitors Effective against influenza A and B Oseltamavir and zanamavir approved for prophylaxis Influenza Surveillance Monitor prevalence of circulating strains and detect new strains Estimate influenza-related morbidity, mortality, and economic loss Rapidly detect outbreaks Assist disease control through rapid preventive action 16

17 CDC website on influenza: Vaccine Storage and Handling Store influenza vaccines in a refrigerator between 2 C 8 C (36 F 46 F) Do not freeze the vaccine Store influenza vaccines in: - The original packaging with the lids closed - A clearly labeled bin and/or area of the storage unit Vaccine storage label examples Available at 17

18 Influenza Resources ACIP s influenza recommendations web page CDC s influenza web page Immunization Action Coalition influenza web page Children s Hospital of Philadelphia Vaccine Education Center influenza web page PLEASE PLACE QUESTIONS IN THE BASKET 18