varicella zoster update on vaccination
DESCRIPTION
Varicella zoster update on VaccinationTRANSCRIPT
Varicella Zoster Vaccination update
Dr.T.V.Rao MD
Dr.T.V.Rao MD 1 4/13/2012
Herpesviridae
• The Herpesviridae are a large family
of DNA viruses that cause diseases in
animals, including humans The family
name is derived from the Greek word
herpein ("to creep"), referring to the
latent, relapsing infections typical of
this group of viruses. Herpesviridae
can cause latent or lytic infections.
Dr.T.V.Rao MD 2 4/13/2012
Herpes Viruses DNA group
• Most important
Human Pathogens
• Wide Host cell range
• Life Long Infection –
Periodic reactivation
• Immunocompromised
• Large number of
genes,
• Some viruses
susceptible to
treatment. Dr.T.V.Rao MD 3 4/13/2012
Varicella
Zoster
Dr.T.V.Rao MD 4 4/13/2012
Properties of Virus.
• Like Herpes
Virus
• Icosahedrons
shape ds
DNA
Dr.T.V.Rao MD 5
4/13/2012
Properties of Herpes
Viruses.
• Spherical in Shape
• Icosahedral 150
to 200 nm in size
• Genome – Double
stranded DNA
Linear
• Envelope contains
Glycoprotein's
Dr.T.V.Rao MD 6 4/13/2012
Dr.T.V.Rao MD 7 4/13/2012
Varicella Zoster
• Varicella -Chicken pox.
• Contagious Disease
• Mainly Children
Generalized Vesicular eruptions
on Skin and Mucous membranes
Severe manifestations in Adults
and Immune compromised.
Dr.T.V.Rao MD 8 4/13/2012
• Varicella-zoster
virus (Human
herpes virus 3)
• Transmitted by the
respiratory route
• Causes pus-filled
vesicles
• Virus may remain
latent in dorsal root
ganglia
Herpes viruses
Figure 21.10a
Dr.T.V.Rao MD 9 4/13/2012
HERPES VARICELLA ZOSTER
HVZ
• Causes chicken pox -fever + characteristic rash
• variable incubation period 14-21 days
• usually mild in children and more severe in adults
• complications
– secondary infection - uncommon
– varicella pneumonia
– secondary bacterial pneumonia S aureus &
pneumococci
– post-infectious encephalitis
– generalized varicella (in immunocompromised patients)
– congenital and neonatal varicella Dr.T.V.Rao MD 10 4/13/2012
Herpes Zoster
• Rash Limited to
Distribution of Single
Sensory Ganglion In
Adults and immune
compromised patients
• Reactivation of
latent HHV-3
releases viruses
that move along
peripheral nerves to
skin.
Dr.T.V.Rao MD 11 4/13/2012
Clinical Findings.
• Varicella, Incubation 10-20 days
• Fever, Malaise
• Rash Trunk –Face –Limbs – Buccal and
Pharyngeal mucosa
• Lesions at all stages
Macules, Papules, Vesicles, Crusts,
May last 5 days, Hundreds of eruptions.
Dr.T.V.Rao MD 12 4/13/2012
HERPES VARICELLA ZOSTER
HVZ
• Causes chicken pox -fever + characteristic rash
• variable incubation period 14-21 days
• usually mild in children and more severe in adults
• complications
– secondary infection - uncommon
– varicella pneumonia
– secondary bacterial pneumonia S aureus &
pneumococci
– post-infectious encephalitis
– generalized varicella (in immunocompromised patients)
– congenital and neonatal varicella Dr.T.V.Rao MD 13 4/13/2012
Chicken pox.
Dr.T.V.Rao MD 14 4/13/2012
Skin lesions of chickenpox
Dr.T.V.Rao MD 15 4/13/2012
Skin lesions showing
different stages
Dr.T.V.Rao MD 16 4/13/2012
Chicken pox
Dr.T.V.Rao MD 17 4/13/2012
Pathogenesis and Pathology
• Varicella virus enter through
URT/Conjunctiva.
Lymph nodes Viremia
Liver and spleen
Secondary viremia
Infects Mononuclear Cells
Rash Vesicle formation
Dr.T.V.Rao MD 18 4/13/2012
Herpes Zoster • Skin Lesions
• Inflammation of
Sensory Nerves
and Ganglia
• Single Ganglion
• Dorsal root
Ganglion
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Herpes Zoster involving a
Nerve segment
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Complications • Bacterial
Infections
• Viral Pneumonia
• Bleeding
Problems
• Infection of the
brain
Dr.T.V.Rao MD 21 4/13/2012
Other Complications.
• Encephalitis,
• Mother to Child
transmission
• Varicella
Pneumonia.
• Fatal
Complications.
Dr.T.V.Rao MD 22 4/13/2012
Herpes Zoster in
Immune compromised
• HIV / AIDS
• Malignancies.
• Organ
transplantations
• Corticosteroid
usage
• Leukaemia's.
Dr.T.V.Rao MD 23 4/13/2012
Pain and hyperesthesia
Dr.T.V.Rao MD 24 4/13/2012
Laboratory Diagnosis.
Smears --Scrapings from Lesions
Demonstration of Multi nucleated giant cells
Tzanck smears
DNA Demonstration
Cell cultures,
Fluorescent –antibody
ELISA PCR
Dr.T.V.Rao MD 25 4/13/2012
Epidemiology
• Communicable
Disease
• World wide
prevalence
• Common in < 10
year olds.
• Zoster in Adults
Droplet spread
Dr.T.V.Rao MD 26 4/13/2012
Treatment
• Specific treatment is indicated
mainly in Immunodeficient and
elderly subjects and also in
complicated with Varicella
pneumonia,encephalitis,and
disseminated zoster
• Acyclovir and Famiciclovir.
Dr.T.V.Rao MD 27 4/13/2012
Prevention of Chickenpox
Susceptible population
children
adults living in close proximity
Do nothing
Immunize
live attenuated
vaccine
Protect if contact with patient with chickenpox
and at risk of severe disease
Zoster Immune Globulin (ZIG) Dr.T.V.Rao MD 28 4/13/2012
Vaccines available
• A live modified Varicella virus
lyophilised vaccine which can be
stored at low temp is available
for protection
• Children 1 -12 years given single
dose.
• >12 years 2 doses 2 -6 weeks
apart
• High titre serum from
convalescing from herpes zoster
protect Immunocompromised
children.
• But not useful for treatment
Dr.T.V.Rao MD 29 4/13/2012
Varicella Vaccines • Two live attenuated varicella virus vaccines
licensed for use in US: Varivax® and Proquad®
• Both vaccines may be used for first and second
doses of varicella vaccine
• Varivax ® (1,400 pfu) is the single-antigen varicella
vaccine licensed in 1995 for use among healthy
persons aged ≥ 12 months
• Proquad® or MMRV (9,800 pfu) is a combination
measles, mumps, rubella, and varicella vaccine
licensed in 2005 for use among healthy children
aged 12 months-12 years
CDC. Prevention of Varicella. MMWR 2007; 56(No. RR-4) Dr.T.V.Rao MD 30 4/13/2012
Current Varicella Vaccination Policy
in the United States
Implemented routine 2-dose childhood varicella vaccination program in 2006 – 1st dose at age 12-15 months
– 2nd dose at age 4-6 years
– Catch-up vaccination of children and
adolescents who had previously
received one dose
– 2 doses for all adolescents and adults
without evidence of immunity
– Pre-natal screening and post-partum
vaccination
CDC. Prevention of Varicella. MMWR 2007; 56(No. RR-4) Dr.T.V.Rao MD 31 4/13/2012
To vaccinate or not ?
Positive Side • Saves lives
• Saves Money, Time
• Children and Students don’t miss school
• 85% percent affective in preventing disease
• Less likely to develop Shingles
• If someone does get Chicken Pox after vaccination, it usually is a lot less worse than a typical case resulting in a few skin lesions, little to no fever and lasting fewer days
Dr.T.V.Rao MD 32 4/13/2012
Contra-indications and Precautions
for Varicella Vaccination
• Severe allergic reaction to vaccine
component or following a prior dose
• Immunosuppression
• Pregnancy
• Moderate or severe acute illness
• Recent blood product (due to potential
inhibition of response to varicella
vaccination)
CDC. Prevention of Varicella. MMWR 2007; 56(No. RR-4) Dr.T.V.Rao MD 33 4/13/2012
Varicella Vaccination in Certain Groups of
Immunocompromised Persons
• Varicella vaccine may be administered to persons
with isolated Humoral immunodeficiency
• Patients with leukemia, lymphoma, or other
malignancies whose disease is in remission and
those chemotherapy have been terminated ≥ 3
months can receive live-virus vaccines
• Consider varicella vaccination for HIV-infected
children with CD4+ T-lymphocyte percentage of
15% or higher
– Eligible children should receive 2 doses of single-
antigen varicella vaccine 3 months apart
CDC. Prevention of Varicella. MMWR 2007; 56(No. RR-4) Dr.T.V.Rao MD 34 4/13/2012
HIV and Varicella Vaccine
• Data on use of varicella vaccine in
HIV-infected adolescents and adults
lacking, but safety is likely to be
similar to response in HIV-infected
children. Vaccination may be
considered for HIV-infected persons
with CD4+T-lymphocyte count ≥ 200
cells/ml
Dr.T.V.Rao MD 35 4/13/2012
Post-exposure Prophylaxis • Varicella vaccine recommended for use in
healthy persons without evidence of
immunity within 3-5 days after exposure
to varicella
– ≥ 90% effective in preventing varicella if
vaccinated within 3 days of exposure and ~ 70%
effective in preventing varicella and ~100%
effective in modifying severe disease if given
within 5 days
– Vaccination still recommended for those with no
other evidence of immunity even after 5 days of
exposure because it will help provide protection
against future exposures CDC. Prevention of Varicella. MMWR 2007; 56(No. RR-4) Dr.T.V.Rao MD 36 4/13/2012
Varicella Vaccine Adverse Events
• Non-serious adverse events
• Rash, Fever
Injection site reactions
• Possible vaccine failure
• Serious adverse events are rare
• Encephalitis Ataxia
• Pneumonia Arthritis
• Hepatitis Vasculitis
• Thrombocytopenia
Chaves J Infect Dis 2008 Dr.T.V.Rao MD 37 4/13/2012
Use of Hyper immune Globulins
in Varicella Infection
• Varicella Zoster
Immune Globulin
(available
product,
VariZIG™) recommended for
certain groups at high
risk for severe
disease within 96
hours after exposure
Dr.T.V.Rao MD 38 4/13/2012
To Vaccinate or Not ?
Other Side • Vaccine is new. Don’t know about long
term side affects yet
• Chicken Pox is usually pretty harmless. No use in vaccinating
• The vaccine is only expected to be effective for 20 years. Those who were vaccinated will need a booster shot. Between the time the original shot wears off and the booster shot, those who were vaccinated can now develop Chicken Pox later in life when its more dangerous Dr.T.V.Rao MD 39 4/13/2012
People who should not be
vaccinated • If you had a serious allergic reaction to Chicken
Pox vaccine
• You have a moderate to serious illness
• You’re pregnant
• Unable to fight off serious infection
• People that have been vaccinated for Chicken
Pox can still get Shingles, but they are less likely
than someone that hasn’t been vaccinated to get
it
Dr.T.V.Rao MD 40 4/13/2012
• Programme Created by
Dr.T.V.Rao MD for Medical and
Health Care Workers
Dr.T.V.Rao MD 41 4/13/2012