A Call To Arms: The Basics for Select Vaccines

Transcription

1 Page 1 A Call To Arms: The Basics for Select Vaccines A Call To Arms: The Basics for Select Vaccines Wendy Rosenthal, Pharm.D. A Call To Arms: The Basics for Select Vaccines Vaccine Science Basics of Immunity

2 Page 2 Vaccination Types of Vaccines Active immunity produced by vaccine Immunity and immunologic memory similar to natural infection but without risk of disease Live attenuated Weakened form of the original Must replicate in body to be effective Generally require one dose Severe reactions possible Examples: measles, varicella, intranasal influenza Epidemiology and Prevention of Vaccine-Preventable Diseases 9 th ed Epidemiology and Prevention of Vaccine-Preventable Diseases 9 th ed Types of Vaccines General Considerations Inactivated Composed for whole viruses or bacteria or fractions Cannot replicate Generally require more than one dose Antibody titer diminishes over time Examples: pneumococcal, HPV, influenza Epidemiology and Prevention of Vaccine-Preventable Diseases 9 th ed Vaccine Adverse Reactions Local Pain, swelling, redness at injection site Usually mild & self-limited Systemic Fever, malaise, headache Live attenuated vaccines: may produce mild symptoms after incubation period of 7 21 days Allergy Due to vaccine components

3 Page 3 General Considerations Contraindications & Precautions Influenza Vaccine Condition Allergy to component Severe illness Pregnancy Immunosuppression Live C P C C Inactivated C P V V C=contraindication P=precaution V= vaccinate if indicated Seasonal Influenza Seasonal Influenza Spreads by contact with infected respiratory droplets Incubation period: 1 5 days Adults are infectious for 1 day prior & 5-7 days following symptom onset Symptoms Sudden onset of fever, muscle aches, headache, malaise, nonproductive cough, sore throat & rhinitis Symptoms resolve in 3-7 days; cough & malaise may persist for > 2 weeks Almost 16 million cases per year in the U.S. among people <20 years of age About 4.5 million per year in the U.S. among the elderly Influenza-related pulmonary and circulatory deaths : average 36,000 Rates of death/100, aged 0 49 years 7.5 aged years 98.3 aged 65 years JAMA. 2003;289:

4 Page 4 Influenza Virus Influenza Antigenic Changes Single-stranded RNA virus Three strains Type A Moderate to severe illness All age groups Subtypes determined by surface antigens: hemagglutinin & neuraminidase Type B Milder diseases Primarily affects children Type C Rarely reported in humans Antigenic Shift Occur only in type A Drastic changes in hemagglutinin or neuraminidase Responsible for epidemics & pandemics Antigenic Drifts Occur in all three types Minor change in surface antigens May result in epidemic Seasonal Influenza Vaccine Composition Seasonal Influenza Vaccine Composition Contains surface proteins of virus strains Most likely to circulate in the coming winter Generally two type A and one type B Epidemiological data reviewed and strains chosen 6 9 months before distribution vaccine A/Brisbane/59/2007 (H1N1)-like virus A/Brisbane/10/2007 (H3N2)-like virus B/Florida/4/2006-like virus vaccine A/Brisbane/59/2007 (H1N1)- like virus A/Brisbane/10/2007 (H3N2)- like virus B/Brisbane/60/2008-like virus

5 Page 5 Seasonal Influenza Vaccines Trivalent inactivated vaccines IM administration Live attenuated vaccines Nasal administration Indicated in healthy individuals 2 49 yo Effectiveness Inactivated influenza vaccine 70 90% effective among healthy persons <65 yo 30 40% effective among frail elderly 50 60% effective in preventing hospitalization 80% effective in preventing death Live attenuated influenza vaccine 87% effective in pediatric population Among healthy adults, 18 37% fewer days of healthcare provider visits Adult Target Groups Adult Target Groups Persons at Increased Risk for Complications Persons aged 50 years Residents of nursing homes and chronic-care facilities Adults with chronic heart or lung disorders, including asthma Adults with: Chronic pulmonary disorders Chronic metabolic disease (e.g., diabetes) Renal dysfunction Hemoglobinopathies Immunosuppression (e.g., HIV) Women who will be pregnant during the influenza season MMWR Persons Who Can Transmit the Virus to Those at High Risk Health care workers Employees of chronic-care facilities or residences for persons in groups at high risk Persons providing home care to persons in groups at high risk Household members (including children) of persons at high risk Household contacts and out-of-home caretakers of children aged <2 years MMWR. 2009

6 Page 6 Target Groups Among Children & Adolescents Shift in Thinking Persons at increased risk for complications: Ages 6 months to 4 years Have chronic pulmonary, cardiovascular, renal, hepatic, cognitive, neurologic / neuromuscular, hematological or metabolic disorders Immunosuppressed Receiving long-term aspirin therapy Residents of long-term care facilities Pregnant during the influenza season Influenza vaccination as personal protection versus Immunization for the greater public good Timing of Vaccination Adverse Effects Inactivated vaccine Staggered administration based on need High risk/health care workers can get as early as Sept, Oct or Nov is ideal Nursing homes October or later Healthy November or later Live attenuated vaccine Starting in October Soreness at injection site Fever, malaise, myalgia Immediate allergic reaction Sneezing or cough (intranasal)

7 Page 7 Inactivated vaccine Egg allergy Contraindications History of anaphylactic reaction to components of the vaccine Live attenuated vaccine Egg allergy History of anaphylactic reaction to components of the vaccine Aged <2 years or >50 years Persons with chronic diseases Pregnant women 2009 H1N1 Influenza Surface antigens & genetics differ from previous strains of influenza Contagious spreading by respiratory route as does seasonal influenza Sings & symptoms similar to seasonal influenza with addition of nausea, vomiting & diarrhea Major Differences 2009 H1N1 Vaccine Composition Seasonal Influenza H1N1 A/California/07/2009 Target Age Highest among <5 and >65 yo Highest among 5 to 24 yo Lowest among > 65 Same egg-based manufacturing processes Hospitalization Rates Greatest among > 65 yo Greatest among < 4 yo Live attenuated & inactivated formulations available Mortality 90% occurs in > 65 yo Median age 37 yo

8 Page 8 Target Populations Adverse Effects Pregnant women People who live with or care for children < 6 months Healthcare & emergency medical services workers People between 6 mo & 24 y Immunocompromised people and those with chronic health issues between the ages of 25 & 64 CDC review of reports to the U.S. Vaccine Adverse Event Reporting System (VAERS) 82 ADRs per 1 million doses distributed compared with 47 reports per 1 million seasonal influenza vaccine doses distributed No substantial differences between H1N1 & seasonal influenza in proportion or types of serious ADR reported Contraindications Inactivated vaccine Hypersensitivity to the vaccine or any component Life-threatening reaction to pervious influenza vaccine Herpes Zoster Vaccine Live attenuated vaccine Same as above Concomitant ASA therapy in children or adolescents Any individual with a hx of asthma Patients with underlying medical conditions Pregnant women

9 Page 9 Clinical Presentation Varicella Zoster Virus (VZV) Varicella (Chicken Pox) Herpes Zoster (Shingles) Herpes Zoster (Shingles) Reactivation of dormant varicella zoster virus Likelihood for reactivation related to: Age Immune status Additional predisposing factors Local irradiation, trauma & surgery Incidence of Herpes Zoster Herpes Zoster (Shingles) 90% of U.S. population has serologic evidence of varicella 50% of persons who live to age 85 will develop herpes zoster Estimated 1 million cases occur yearly in U.S. Symptoms Sharp, stabbing pain & tenderness along the nerve Lesions appear 3 5 days later Papules vesicles pustules Heal in 7 10 days Present on only one side of the body Contagious until dry crusts appear: 5 10 days Pain can occur during the prodrome and/or eruptive phase

10 Page 10 Herpes Zoster (Shingles) Serious complications Postherpetic neuralgia (PHN) 90% pain-free 1 month after acute attack; 95% pain-free at 3 months & 97% pain-free after 12 months Incidence & duration directly correlate with patient age Results from varicella-induced neuronal destruction & immflammation Difficult to treat Scarring, bacterial superinfection, cranial and motor neuron palsies, pneumonia, encephalitis, visual impairment, hearing loss Herpes Zoster Vaccine (Zostavax ) Live, attenuated varicella-zoster virus Indication: prevention of HZ in individuals 60 and older Stimulates the patient s immune system to reestablish memory cells Dose: 0.65 ml subq Herpes Zoster Vaccine (Zostavax ) Herpes Zoster Vaccine Advisory Committee On Immunization Practices (ACIP) recommendations Routinely administer to all people 60 years of age and older This includes those who have had a previous episode of the disease Patients need not be asked about history of varicella or have varicella immunity determined by serologic testing Must be kept frozen at -15º C (+5º F) Reconstitute straight from freezer and use immediately Adverse effects: injection site reactions

11 Page 11 Contraindications History of anaphylactic reaction to gelatin, neomycin, or other component of the vaccine Immunodeficiency (leukemia, lymphomas, other bone marrow or lymphatic neoplasms, HIV) Immunosuppressive therapy Active, untreated tuberculosis Pregnancy Efficacy Herpes Zoster Vaccine Efficacy with respect to incidence of zoster was 63.9% among those yo compared with 37.6% in those 70 years and older Reduced incidence of postherpetic neuralgia by 67% Duration of time patients experienced pain was significantly lower in those who received the vaccine N Engl J Med 2005:352; Human Papillomavirus (HPV) Vaccine Human Papillomavirus DNA tumor virus Skin virus About 40 genital types 15 to 18 of these associated with cancer Sexually transmitted disease Intercourse Genital, oral & skin to skin contact

12 Page 12 Epidemiologic Relationships of HPV Common HPV Types Associated With Benign and Malignant Disease Cervical dysplasia and cancer Genital warts Anogenital cancers (vulvar, penile, vaginal) Head & neck cancers (esophagus, pharynx) High-Risk HPV Types Types 16, 18, 31, and 45 Low-Risk Types 6 and 11 Manifestations Low-grade cervical changes High-grade cervical changes Cervical cancer Anogenital and other cancers Benign low-grade cervical changes Condylomata acuminata (Genital warts) Most HPV Infections Resolve HPV HPV clearance 80 90% of infections resolve in 2 years Average duration of infection 9 13 months Unclear if eradicated or latent HPV persistence 10 20% of infections persist Major risk factor for cancer Clearance & persistence are age related 6.2 million new cases of sexually transmitted HPV occur in the U.S. each year 20 million people in the U.S. currently have a detectable genital HPV infection 50% of sexually active men and women acquire genital HPV infection at some point in their lives $1.6 billion in direct annual medical costs for treating symptoms of genital HPV infection

13 Page 13 External Genital Warts (EGW) 1 million new cases annually; two thirds in women Present in 15% of general population Transmitted during vaginal or anal sex with infected partner May appear within several weeks, months or years after sex or not at all Occur predominantly at sites of friction Penis, scrotum, vulva, vagina, cervix, perineum & perianal area External Genital Warts (EGW) Can spontaneously disappear without treatment May remain unchanged or increase in size and/or number Treatment options Provider applied topical medications Patient applied topical medications Freezing, laser and surgical excision Recurrence rates of 30-40% Gardasil HPV Vaccines Quadrivalent vaccine containing HPV-like particles of HPV types 6,11,16 & 18 Cervarix Bivalent vaccine containing HPV-like particles of HPV types 16 & 18 Indications: Gardasil Approved for use in females aged 9 to 26 for prevention of the diseases caused by HPV types 6,11,16 & 18: Cervical cancer Vaginal cancer Vulvar cancer Genital warts And the following precancerous or dysplastic lesions: Cervical adenocarcinoma in situ (AIS) Cervical intraepithelial neoplasia (CIN) grade 2 & 3 Vulvar intraepithelial neoplasia (VIN) grade 2 & 3 Vaginal intraepithelial neoplasia (VaIN) grade 2 & 3 Cervical intraepithelial neoplasia (CIN) grade 1

14 Page 14 Indications: Gardasil Indications: Cervarix Approved for use in males aged 9 to 26 for prevention of genital warts caused by HPV types 6 &11 Approved for use in females aged 10 to 25 for prevention of the diseases caused by HPV types 16 & 18: Cervical cancer And the following precancerous or dysplastic lesions: Cervical intraepithelial neoplasia (CIN) grade 2 Cervical intraepithelial neoplasia (CIN) grade 1 Gardasil Administration Given as 3 separate IM injections over 6 months 1st dose: at elected date 2nd dose: 2 months after 1st dose 3rd dose: 6 months after 1st dose Cervarix Given as 3 separate IM injections over 6 months 1st dose: at elected date 2nd dose: 1 month after 1st dose 3rd dose: 6 months after 1st dose Adverse Effects: Gardasil As of , 12,424 adverse events reported since approval 94% classified as nonserious 6% classified as severe Most common events Syncope Local reactions at injection site Nausea Headache Vasovagal syncope High baseline risk among target population 15 waiting period following administration FDA & CDC: effective & benefits continue to outweigh risks JAMA Aug

15 Page 15 Adverse Effects: Cervarix ACIP Provisional Recommendations Reported in approx 20% of study vaccine recipients Pain at injection site Fatigue Headache GI symptoms Arthralgia Females Routine vaccination of females aged 11 or 12. Can be started as young as 9 yo Females aged who have not been previously vaccinated Use either the bivalent HPV or quadrivalent vaccine for prevention of cervical cancers & precancers Recommends quadrivalent HPV for prevention of cervical cancers & genital warts (This also protects against vular & vaginal cancers) Males Quadrivalent vaccine may be given to males 9 to 26 to reduce likelihood of acquiring genital warts Use in Sexually Active Females Questions? HPV vaccine is a prophylactic vaccine Individuals infected with 1 or more vaccine-related HPV types prior to vaccination will achieve protection from the remaining vaccine HPV types