what's all the fuss with vaccinations?
DESCRIPTION
Dr. Maynard reviews the importance of vaccination for the health and safety of children, and adults alike. (originally presented 8.15.12)TRANSCRIPT
What’s all the fuss with vaccinations?
Presented by Dr. Roy Maynard
August 15, 2012
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Objectives
• Understand the role of antigenic drift and shift in
influenza
• Recognize differences in influenza vaccinations
• Describe mechanism of action of anti-influenza drugs
• Identify American Academy of Pediatrics
Recommendations for influenza vaccination for the
2012-2013 season
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Definition
• Edward Jenner 1796 used cowpox (variola
vaccinia) to inoculate
• Individuals inoculated with cowpox were
protected against smallpox
• The term “vaccine” derived from this historical
perspective
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Definition
• A vaccine is a biological preparation that
improves immunity to a particular disease
• Flu shot: split-virus vaccine, trivalent since 1945
• Nasal spray: LAIV (live attenuated influenza
virus) since 2003
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Dr. Edward Jenner
http://www.ourcivilisation.com/smartboard/shop/jennere/about.htm Accessed 8/14/12
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Smallpox
http://en.wikipedia.org/wiki/Smallpox Accessed 8/14/12
Bangledesh (1973) USA (1912)
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Smallpox
• Mortality 30 in severe form
• Mortality 40-50% for children less than one
year of age
• 18th century killed 400,000 people/year in
Europe
• 300-500 million deaths during the 20th century
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Smallpox
• Last case reported in 1973
• Immunization programs for smallpox
discontinued
• Smallpox has been eradicated
• Success story for global immunization to
eradicate a devastating disease
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Types of Vaccines
• Killed: influenza, cholera, polio, hepatitis A, bubonic plague, rabies
• Attenuated: measles, rubella, mumps, yellow fever, typhoid, BCG
• Subunit: surface proteins or particles only, hepatitis B, influenza, HPV
• Conjugate: polysaccharides poorly immunogenic, link to protein get better response, HIB vaccine
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Types of Vaccines
• Valences: polyvalent like PCV 7, now PCV 13
• Toxoid: toxic compound is inactivated but used in the vaccine, tetanus, diptheria
• Passive immunization: synagis
• Experimental: DNA vaccines, cancer vaccines
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Influenza
http://www.nytimes.com/2006/12/26/health/26cons.html?_r=1 Accessed 8/14/12
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Transmission
• Droplet transmission from coughing or
sneezing
• Nasal secretions
• Incubation period is 1-5 days
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Presentation
• Starts with rhinitis, pharyngitis and cough
• High fever
• Chills
• Muscle aches
• Headache
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Anatomy of Influenza Virus
www.environment.ucla.edu/CTR/research/Inf-Diseases/avian_influenza.html Accessed 8/14/12
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Anatomy of Influenza Virus
• Orthomyxovirus single stranded RNA virus,
8 pieces
• Surface antigens
– Hemagglutin (HA) – determines extent of
infection by binding to host cells (H1-H17)
– Neuraminadase (NA) – breaks down glycoprotein
link so new virus can be released from host cell,
target of Tamiflu (N1-N9)
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Anatomy of Influenza Virus
http://www.abc.net.au/health/library/stories/2004/07/08/1831345.htm Accessed 8/14/12
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Influenza Virus
• Influenza A, B and C
• A is highly mutagenic, antigenic shift
• A causes more severe disease
• Seasonal flu in winter
• Pandemic influenza occurs when new A virus appears and population has no immunity
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Viral Replication
https://dokuwiki.noctrl.edu/doku.php?id=bio:440:rabies Accessed 8/14/12
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Antigenic Drift
http://en.wikipedia.org/wiki/File:Antigenic_drift_vs_shift.png Accessed 8/14/12
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3 Horses of the Apocalypse
http://jspivey.wikispaces.com/file/view/bird_flu_2.JPG/34372223/bird_flu_2.JPG Accessed 8/14/12
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Antigenic Shift
http://en.wikipedia.org/wiki/Antigenic_shift Accessed 8/14/12
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Complications
• Bacterial pneumonia and other bacterial infections
• Viral pneumonia
• Croup, bronchiolitis in children
• Encephalitis
• Myocarditis
• Reye’s Syndrome
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Influenza Deaths
• 3,000 to 49,000 deaths/year; average is 23,000 deaths/year
• Healthy people get the flu
• HEALTHY PEOPLE DIE FROM THE FLU (secondary bacterial pneumonia)
• 2009 H1N1 pandemic USA 12,500 deaths
• 2009 H1N1 pandemic USA 90% of hospitalizations and deaths in people <65 years of age
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Influenza Associated Pediatric Deaths
• 46 deaths in 2005-2006
• 282 deaths in 2009-2010 (H1N1 pandemic)
• 26 confirmed deaths in 2011-2012 by CDC
– 50% had no known risk factor except age
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Treatment
• Tamiflu oseltamivir (Tamiflu), zanamivir, amantadine, rimantadine (treat early or for chemoprophylaxis)
– Active against neuraminadase
– Resistance prevalent
• F16 antibody – active against all A viruses, active against HA
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Influenza Shot
http://bulldogblog.csufresno.edu/articles/wp-content/uploads/2009/09/flu-shot-cartoon.jpg Accessed 8/14/12
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Side Effects of Flu Shot
• Serious side effects are very rare
• Inactivated virus – YOU CANNOT GET INFLUENZA FROM THE VACCINE
• Mild reaction, lasts 24-48 hours, soreness, redness or swelling where the shot was given (20%), fever, aches, headache, fatigue, hoarseness, red or itchy eyes (1%)
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Side Effects of Flu Shot
• Moderate reactions: febrile seizures in children receiving flu shot and PCV13, more of a problem in children with a history of febrile seizures
• Severe problems: life-threatening allergic reactions, Guillain-Barre Syndrome
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Egg Allergy
http://www.ifpma.org/resources/influenza-vaccines/influenza-vaccines/vaccine-manufacture-virus-harvesting.html Accessed 8/14/12
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Egg Allergy
• Skin testing no longer necessary
• Use lowest ovalbumin-containing vaccine
• Get immunization in office where emergency equipment is available
– First approach: get 1/10th dose, wait 30 minutes, get remainder and wait 30 minutes
– Second approach: get full dose, wait 30 minutes
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Side Effects of LAIV
• Runny nose
• Headache
• Vomiting
• Muscle aches
• Fever not common in adults
• Viral shedding up to 7 days
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Influenza Vaccine Effectiveness
• 60% across the board
• 90% effective in young people, 30-40% effective in >65 years of age
– Different strains chosen for the vaccine
– Immune system of the individual
– Intranasal live virus vaccine available
– Shots are inactivated virus
– Safe but not always effective
• Flu shot and Flu mist comparable
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Influenza Vaccine Effectiveness
• 25 deaths prevented per 100,000 people
vaccinated
• 1 death prevented for every 4,000
vaccinated
• Protects against hospitalization and death
for those vaccinated even if they get
clinical disease
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American Academy of Pediatrics (AAP)
Recommendations for 2012-2013 Flu Season
• Recommend influenza vaccination for all
people including children and adolescents
over 6 months of age
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American Academy of Pediatrics (AAP)
Recommendations for 2012-2013 Flu Season
• Special Efforts
– Children >6 months with chronic disease (asthma,
diabetes, prematurity, BPD, immunosuppression,
neurological disorders)
– Out-of-home providers of high risk children <5 years
of age and especially <6 months of age
– All health care personnel
– Women who are pregnant, planning to be pregnant,
who have recently delivered or are breast feeding
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Conclusions
• Influenza is a potentially fatal disease
• Generally affects the very young and the very old
• Pandemics are associated with influenza A after
antigenic shift and affects a population with no
immunity
• Pandemics affect all ages in a population
• Scientific data supports protective effect of flu
vaccine
• Generally safe, not always effective
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Get Immunized
• Protect yourself
• Protect your family
• Protect your co-workers
• Protect your patients
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Q & A
Questions?
Thank you for attending!