VARICELLA
VACCINE
What
is varicella?
Varicella or chickenpox is a highly contagious disease with peak age
at 5-9 years leading to rash. It is a self-limiting disease and occasionally
leads to fever, pneumonia, liver damage and brain infection. Chicken
pox can be very severe in immunocompromised patients e.g. in patients
with cancer and can even lead to death.
If
it occurs during pregnancy, there are 25% chances of transmission of
the virus to fetus. If it occurs in first half of pregnancy it will
lead to fetal varicella syndrome characterized by scarred skin, limb
defects and eye defects. If it occurs in 2nd half of pregnancy, the
child has chances of developing herpes zoster at an early age.
If
it occurs within 21 days of delivery, there are 25% chances of newborn
developing chicken pox.
Which
high- risk group should receive Varicella vaccine and why?
Varicella vaccine is definitely indicated in certain high-risk groups:
- Immuno-compromised
host: Varicella can be very severe in immunocompromised host as
seen before. Hence such children should be immunized irrespective
of age. One needs to give 2 doses of injections. Care should be
taken to stop chemotherapy/steroids for at least 2 weeks before
and after vaccination or at least for the first dose of vaccination.
- Healthy
adults and adolescents (>13 yrs. old): Those with no definite
history of chicken pox in the past can be assumed to be susceptible,
as subclinical cases of varicella are rare. Such patients have high
morbidity and occasional mortality if they develop chicken pox.
Ideally all such adults should be vaccinated but specially the following
high risk groups:
i)
Non-pregnant women of childbearing age.
ii) Adults in contact with children who are at high risk of complications
of chicken pox e.g. family members of a child with leukemia.
iii) Those at high risk of exposure to chickenpox like teachers
of young children, college students, day-care nursery workers, military
personnel etc.
iv) Health personnel.
What
about normal children? Who should be given the varicella vaccine?
Universal vaccination of all children at 15-18 months of age has been
advocated in some countries including USA of late.
A
normal child who develops chickenpox suffers for 1-2 weeks of disease.
The complications are rare and mortality even more rare. But there are
occasional cases of complications like encephalitis, pneumonia and even
death in normal children. More important, it leads to social problems
like the child missing school or even final exams as it usually occurs
in months of Jan- March every year. Even the parents will have to take
leave and lose wages for 7-14 days.
On
the other hand, the vaccine is very costly. The cost is approximately
Rs. 1250/- per dose. There are 2-3% chances of developing vaccine induced
rash immediately after vaccination and 2-8% chances of breakthrough
varicella at a later age. Both these problems are mild and without any
complications.
The parents must be explained the pros and cons of giving or not giving
the varicella vaccine. The choice is then left to the parents whether
they would want to give the vaccine to their child or not.
Last
updated on 02-12-2003
