Chickenpox is caused by the varicella zoster virus and causes a itchy rash. A vaccine was developed in 1974 and is recommended for children and adults in two doses to provide protection. The vaccine greatly reduces the risk of infection if given within 3 days of exposure and results in a milder case of chickenpox if breakthrough infection occurs. For older adults, a new shingles vaccine called Zostavax was approved to help prevent reactivation of the virus and development of shingles. While vaccines provide protection, questions remain around the necessity of routine chickenpox vaccination.

1. Trends in Vaccination for Herpes Zoster (Chickenpox)
Dr.T.V.Rao MDChickenpox is a highly contagious disease caused by primary infection with
varicella zoster virus (VZV). It usually starts with vesicular skin rash mainly on the body and head
rather than at the periphery and becomes itchy, raw pockmarks, which mostly heal without scarring.
On examination, the observer typically finds skin lesions at various stages of healing and also ulcers
in the oral cavity and tonsil areas. It can spread easily; one can get it from an infected person who
sneezes, coughs, or shares food or drinks. We can also get it if we touch the fluid from a chickenpox
blister. A person who has chickenpox can spread the virus even before he or she has any symptoms.
Chickenpox is most easily spread from 2 to 3 days before the rash appears until all the blisters have
crusted over Chickenpox is most easily spread from 2 to 3 days before the rash appears until all the
blisters have crusted over.A varicella vaccine was first developed by Michiaki Takahashi in 1974
derived from the Oka strain. It has been available in the US since 1995 to inoculate against the
disease. Some countries require the varicella vaccination or an exemption before entering
elementary school. Protection from one dose is not lifelong and a second dose is necessary five
years after the initial immunization, which is currently part of the routine immunization schedule in
the US. The chickenpox vaccine is not part of the routine childhood vaccination schedule in the UK.
In the UK, the vaccine is currently only offered to people who are particularly vulnerable to
chickenpox. A vaccinated person is likely to have a milder case of chickenpox if infected
Chickenpoxvaccine protects us against a very uncomfortable and sometimes serious disease. CDC
recommends two doses of chickenpox vaccine for children, adolescents, and adults. Children should
receive two doses of the vaccine—the first dose at 12 through 15 months old and a second dose at 4
through 6 years old. Two vaccines containing varicella virus are licensed for use in the United States.
Varivax® is the single-antigen varicella vaccine. ProQuad® is a combination measles, mumps, rubella,
and varicella (MMRV) vaccine. Both vaccines contain live, attenuated varicella-zoster virus derived
from the Oka strain.All adults who have never had chickenpox or received the vaccination should be
vaccinated against it. Two doses of the vaccine should be given at least four weeks apart. If you've
never had chickenpox or been vaccinated and you are exposed to chickenpox, being vaccinated right
away will greatly reduce your risk of getting sick. Studies have shown that vaccination within three
days of exposure is 90% effective at preventing illness; vaccination within five days of exposure is
70% effective. If you do get sick, the symptoms will be milder and shorter in duration. According to
the study, published last week in The Journal of the American Medical Association, found the
effectiveness of the vaccine is found to fade substantially a year after it is administered. Varicella is
not included in the National Immunization Program. But the Indian Academy of Paediatrics (IAP)
places Varicella under optional vaccines. Varicella can be given to children once they're older than
15months.In IAP categorization, Varicella is placed in Category 3 which are 'vaccines to be given
after one discussion with parents'. Other vaccines in this category are Hepatitis A,
Rotavirus...etc.How effective is this vaccine? Almost all (97%) children between age 12 months and
12 years develop immunity to the disease after one dose of vaccine. For older children and adults, an
average of 78% develops immunity after one dose and 99% develop immunity after the
recommended two doses. Although some vaccinated children (about 2%) will still get chickenpox,
they generally will have a much milder form of the disease, with fewer blisters (typically fewer than
50), lower fever, and a more rapid recovery. The vaccine almost always prevents against severe
disease. Getting chickenpox vaccine is much safer than getting chickenpox disease. Can the vaccine

2. protect you if you've already been exposed to chickenpox? Yes, it is 70–100% effective if given
within 72 hours of exposure. Can the vaccine cause chickenpox? Because this vaccine is made from a
live, but weakened, virus, about 1% of recipients develop a mild form of the disease, consisting of a
limited rash, most often with only 5–6 blisters. Usually there is no fever. These people are then safe
from the more serious, naturally occurring form of the virus. (Adapted from
www.vaccineinformation.org)
ZOSTAVAX is new vaccine it is a live attenuated virus vaccine indicated for prevention of herpes
zoster (shingles) in individuals50 years of age and older.Merck & Co., Inc. announced that the U.S.
Centres for Disease Control and Prevention’s Advisory Committee on Immunization Practices (ACIP)
voted unanimously to recommend that adults 60 years of age and older be vaccinated with
ZOSTAVAX? [Zoster Vaccine Live (Oka/Merck)] to help prevent shingles (herpes zoster) ZOSTAVAX
was approved by the U.S. Food and Drug Administration (FDA) on May 25 for the prevention of
shingles in individuals 60 years of age and older. ZOSTAVAX is not a treatment for shingles or post
herpetic neuralgia (long-term nerve pain that can be a complication of shingles). ZOSTAVAX is given
by a single dose by injectionLimitations of ZOSTAVAX: --ZOSTAVAX is not indicated for the treatment
of zoster or post herpetic neuralgia (PHN) ZOSTAVAX is not indicated for prevention of primary
varicella infection (Chickenpox)SC- The recommended dose is 0.65-mL as a single dose, in the deltoid
region of the upper arm.CONTRAINDICATIONS- include History of anaphylactic/anaphylactoid
reaction to gelatin, neomycin, or any other component of the vaccine, Immunosuppression or
Immunodeficiency;one should not be confused with utility of ZOSTAVAX, from the other vaccines
used for primary prevention of Chickenpox with earlier vaccines, In spite of availability of several
vaccines the question, and is it highly essential to take Vaccination for Chickenpox? Not well
answered. (for more information Search CDC Atlanta)
Dr.T.V.Rao MD Professor of Microbiology A freelance writer