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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LAIV

http://flushotsideeffect.com/ Accessed 8/14/12

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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!