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Varicella Vaccine
Recommendations
for Postexposure Prophylaxis of Varicella of
Persons at High Risk for Severe Disease
Clinical
questions and answers
Questions and
links to answers:
- What
is recommended for postexposure prophylaxis
following varicella exposures among persons
at high risk for severe disease?
- What
are the indications for VZIG use?
- When
should VZIG be administered?
- What
is the recommended dosage?
- How
can I obtain VZIG for a patient in need?
- Is
there a shortage of VZIG?
Go to other
pages of related questions:
-
What is recommended for postexposure
prophylaxis following varicella exposures
among persons at high risk for severe disease?
Varicella
zoster immune globulin (VZIG) is recommended
for postexposure prophylaxis for persons
at high risk for severe disease and complications.
- What
are the indications for VZIG use?
The Advisory
Committee on Immunization Practices and the
American Academy of Pediatrics (AAP) indicate
that the decision to administer VZIG to a
person exposed to varicella-zoster virus
(VZV) should be based on whether a) the patient
is susceptible (either by having a negative
history of varicella or by lacking documentation
of vaccination), b) the exposure is likely
to result in infection, and c) the patient
is at greater risk for severe disease and
complications than the general population.
(http://www.cdc.gov/mmwr/preview/mmwrhtml/00042990.htm).
Several
types of exposure can place susceptible persons
at risk for varicella. Direct contact exposure
is defined as greater than 1 hour of direct
contact with an infectious person while indoors;
substantial exposure for hospital contacts
consists of sharing the same hospital room
with an infectious patient or prolonged,
direct, face-to-face contact with an infectious
person (e.g., health-care workers). Brief
contacts with an infectious person (e.g.,
contact with x-ray technicians or housekeeping
personnel) are less likely to result in VZV
transmission than are more prolonged contacts.
Persons
at greater risk for severe varicella and
for whom VZIG is recommended include:
Persons aged <13 years
-
Immunocompromised
children - including children
who have primary and acquired immunodeficiency
disorders, neoplatic diseases, and are
receiving immunosuppresive treatment.
ACIP recommends that, to ensure protection
against severe disease, immunocompromised
persons receiving regular IGIV should
be administered VZIG if exposed to wild-type
VZV.
-
Neonates whose mothers have signs and
symptoms of varicella within 5 days before
to 2 days after delivery
-
Neonates exposed postnatally,
specifically premature infants born to
susceptible mothers because their immune
system may be compromised. These infants
should be considered at risk for as long
as they are hospitalized. Premature infants
who are < 28 weeks’ gestation
or who weigh < or = 1,000 g at birth
who are exposed to VZV should receive
VZIG regardless of maternal history.
VZIG is not recommended for healthy,
full-term infants who are exposed postnatally,
even if their mothers have no history
of varicella infection (with the exception
of those neonates mentioned in the previous
bullet).
Persons
aged > or =13 years
-
Immunocompromised
adolescents and adults
-
Healthy adolescents and adults:
For susceptible, healthy adolescents
or adults, although varicella is more
severe than in healthy children, the
decision to administer VZIG should be
made on an individual basis. The objective
of using VZIG among healthy adolescents
and adults is to modify, rather than
to prevent, illness with the hope of
inducing lifetime immunity. For this
group, vaccination within 3-5 days of
exposure also is beneficial in preventing/modifying
varicella.
-
Pregnant women
-
Hospital personnel
- When
should VZIG be administered?
VZIG treatment
is expected to be most effective when it
is initiated within 96 hours after exposure.
Treatment after 96 hours is of uncertain
value.
- What
is the recommended dosage?
The recommended
dose is 125 U/10kg (22 lbs) of body weight,
up to a maximum of 625 U. VZIG should be
administered intramuscularly as directed
by the manufacturer.
- How
can I obtain VZIG for a patient in need?
VZIG can be
obtained from the sole authorized US distributor,
FFF Enterprise (Temecula, CA). VZIG can be
ordered from FFF Enterprises, at 1-800-843-7477
or via the Internet at www.fffenterprises.com.
FFF Enterprises delivers VZIG on an as needed
basis (e.g., when there is an identified
exposed person for whom VZIG is indicated).
Under normal circumstances, the distributor
delivers the vaccine within 24 hours of request.
Currently, VZIG is available only in 625-U
vials. Pediatric VZIG (125-U vial) are no
longer available and clinicians should use
the appropriate volume from the 625-U vial
when VZIG is indicated.
Additional
information on VZIG use can be found in the
1996 ACIP recommendations for prevention
of varicella (MMWR 1996;45:20-24; http://www.cdc.gov/mmwr/preview/mmwrhtml/00042990.htm).
- Is
there a shortage of VZIG?
No. The sole
producer of VZIG in the United States has
ceased production of VZIG. However, there
is sufficient supply of 625-U vials of VZIG
at the moment, and can be obtained from FFF
Enterprises. (http://www.fda.gov/cber/infosheets/mphvzig092005.htm).
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